Whoa, hold up a second. Ryuga? He hasn't played Ike since he mained Corrin which is a looong time ago (apparently right now he's going through a crisis with Corrin recently) while Ryo hasn't traveled as much lately and plays a mix of Roy, Corrin, and Ike. The Ike players with the best results are usually divided between San, Ryo, SM, and a few other lesser known players I can't recall at the moment, each placing at a range of top 8 to top 16-32. I dunno, just judging by the rest of this post you don't seem all that familiar with the character, especially when you say he's the least complex (because lets be honest, smash 4 is not a technically demanding game to start with, the majority of the cast is easy to play and master with some practice, so saying Ike is simple doesn't say much). U-throw f-air is guaranteed against nearly all meta relevant characters, and DIing only sets up an easier u-air to KO with anyway. Not sure which scary stuff you're referring to in particular but Ike's best tools are generally safe on shield (when spaced obviously), if thats the standard you're going by for losing to block.
His results have waned since 2016 but its mainly a mix of lacking representation and the best players not competing much lately, doesn't necessarily mean the character is bad. Anyone remember when Samus was considered low tier for like the longest time, even though her latest and most significant list of buffs were given a whole year ago?
Ike's meta hasn't really gone anywhere since Ryuga quit playing him though. I'll admit I should've mentioned SM and San rather than Ryuga though, haven't really been paying that much attention to Ike for quite some time since he never does anything new of relevance. However, you can't just go on to say "judging by the rest of this post you don't know what you are talking about" after having pointed out one flaw which is of no relevance to the bulk of my argument. You have to.. you know.. like actually argue yourself.
Speaking of which, its funny how you make it sound like Ike has several players getting stuff that matters done by saying
"The Ike players with the best results are usually divided between San, Ryo, SM, and a few other lesser known players I can't recall at the moment, each placing at a range of top 8 to top 16-32." before you dismiss my post using no arguments of your own. Please tell, how is it relevant that the players you mentioned plus the ones you didn't mention but claimed to exist place at a range of top 8 to top 16-32 without taking into consideration the frequency of their placings and what type of tournaments they place at? As I said before, you shouldn't dwell into results if you want to argue in favor of Ike.
It's also funny how your one concrete argument for me not knowing much about Ike is that I think he lacks complexity. Well, actually.. what you said was that I said he was THE least complex which constitutes strawmanning, but whatever. Anyway he is one of the least complex and its relevant for several reasons. His lack of complexity makes it so that its easy to tell he has no room for development, it does away with arguments based around supposing potential. Its also relevant because since there's few ways to play Ike, you can't vary his playstyle like you can with other more option rich characters, this also means that the way Ike is played wont vary that much from player to player, all in all meaning that learning the Ike MU isn't very hard (there goes a little more potential, or would go if there was any). Take his neutral, he has to overly rely on a few good moves, if the opponent is able to work around those the nature of his neutral (abysmal) is quickly evidenced.
Moreover, Sm4sh isn't that easy a game to play there's plenty of difficult stuff in it even by fighting game standards, sure it is easy if you compare it to melee but why the need for that again? And besides, you are mixing things up. A game or character can be complex without being difficult execution wise. You strawman me yet again by arguing as if though I was talking about difficulty in terms of execution when I was talking about complexity. It just so happens that Ike is also pretty easy input wise (oh poor potential).
Now about uthrow>fair and uthrow>uair, the former doesn't have that big a window within which the combo is true AND kills, against some chars its really small, its also heavily dependent on stage position, and how stale fair is (it pretty much always is to some degree, oftentimes to a large degree), might sound like a reliable kill on paper, but in practice it isn't for the reasons I mentioned, you also have to factor in that Ike doesn't have a very good grab either (tho fair being strong and scary does allow him tomahawks, and he has them jab cancels too). If you look at actual top level Ike play you should be able to see what I'm saying in practice. But since almost no one plays Ike few understand whats going on when they do see footage. The window for uthrow>uair isnt big either, and when you say that DI'ing to avoid fair sets up for an easier kill with uair you make it sound like a strength of his that he requires a DI read for his throw to confirm into a kill when that is in fact a pretty big weakness compared to not needing such a read (it doesn't always need such a read, close enough to the ledge against a char with the right properties and DI wont help). I don't want to downplay Ike's grab game tho, it is a good grab game and one of his selling points, it just doesnt grant him reliable kill confirms like those other chars such as DK, Bowser or Robin get. Again, footage confirms this.
Finally, Ike's safe on block stuff is pretty non threatening since his attacks don't eat shield since he is unable to attack repeatedly with safe attacks, and he is unable to exert continued pressure after landing safe on shield moves because his attacks are too laggy, and if the opponent runs away Ike cant give chase without leaving himself open or using very punishable moves. In this regard he is strictly inferior to Cloud. Compare Cloud spacing bairs on shield to Ike doing the same with his fair or his bair for that matter, it just doesnt work with Ike. Also you're wrong in saying most of his scary stuff is safe on block, but meh I cba to go there. This will have to suffice, I feel I've dealt with your feeble attempts at having points now. Edit: still it needs to be said that your Samus analogy is invalid for obvious reasons which I cba to provide. But I will hint that they involve complexity.
I remember talking with San about the future of Ike long time ago and he did mention that people aren't staying grounded enough and are jumping way too. I also remember there being some discussion about using crouch more in neutral. Being able to avoid some moves and punishing them after without need to worry about being forced to suffer shield stun is a big deal for a character like Ike.
I dunno about the future of Ike in singles, but he will stay relevant in doubles due to his high sweeping ability, stock tanking ability and his easy team combo set ups.
He has to stay grounded a lot because his aerials aren't really safe unless done in a retreating fashion and even then they aren't safe if the opponent has good enough movement. On the ground he has a solid OOS punish in jab and a good dash to shield, but his ground game isn't impressive overall. His crouch is hardly amazing either. It kind of says something about the future of the character when these are the things San (a very knowledgeable guy and good player) bring up as areas with room for development.
Also think he isn't bad in doubles but other characters can do similar stuff better there as well, Ike's poor disadvantage and lack of quick get off me moves is bad for dubs. Cloud (obviously I know) is better for dubs, and so is Corrin, sure Ike can dish it out, but he really struggles to defend himself in dubs afaik. Or I dunno, I don't know that much about dubs but from my experience Ike is decent but not really good in dubs.
IMO Ike's utilt is a sick move, I think Ike players could get away with using it more than they do especially perfect pivoted. It can potentially cover a lot of options, trades with jump in aerials or beats them, beats crossups, and beats attempts at rolling in (people who dont get that you are supposed to be patient vs Ike in neutral tend to be easily baited into rolling in), has good duration (I think.. dont remember exact frame data) making it so that it clanks often which the Ike players tend to be ready for unlike their opponents allowing them to capitalize on it. It has good range and a great hitbox covering Ike's back as well, it kills (ridiculously early with rage against non heavies) or puts the opponent in a bad spot all the while leaving a deceptively small window for punishment due to high shieldstun. Just a sick move all in all.
Going with what San said I suppose smart usage of crouching can further enhance it. Spacing fair and even ftilt can trigger a lot of people into attempting to close the gap on Ike by rolling or airdodge jumping or just straight out dashing in if they are fast, utilt is good at punishing all of these responses. Also covers ledge options fairly well, tho Ike has better stuff for that in general. You can also land it after being grab released, but you need the surprise factor for this which requires near instant grab release at higher percentages which requires a sick mash.
Dtilt on the other hand is weird, its not really that good, but since people dont react properly after being hit by it thus allowing followups which aren't necessarily combos to seem like they are its kinda good. Though it bears testimony to Ikes lack of relevance that lots of people still don't know how to play against him, and it says a lot that such a powerful character has so little in terms of results in spite of incompetent opponents.
I hope MKLeo grows tired with Corrin and tries Ike, then maaaaybe we'd see some actual development of his meta.