About the top tiers being easier than lower tiered debate, I guess this is how I see things. Now obviously, you look at top tiers and the difference they have compared to lower tiered characters is options. In any given situation, the higher tiered character will usually have more options than a lower tiered character in the majority of situations. A lot of the time, these options that the higher tiered characters have are stronger too.
This should be a given to most people in the thread, but I just wanted to clear this up just in case the newer people didn't quite understand.
A good example would be comparing the neutrals of Mario and Luigi. In most situations, Mario has more options and stronger options. He has more flexibility with his sh aerials, good mobility to keep up with characters trying to zone him out/zone unwanted nuisances out, FLUDD to control space and to disrupt, fantastic OoS options like up b, cape to deal with projectiles, smash attacks for reads/baits, fireball for a projectile of his own (even if it is a mediocre one), and of course his tilts, grab and jab for close ranged fighting. Now, although it can be hard in some match ups, Mario has the ability to handle any character with some success because his tools in neutral are versatile enough to allow him to be flexible in his approach to get him into an advantaged state (which would be getting close to the opponent and preferably snagging a grab at most percents). He essentially has at least some sort of tool to help him alleviate any type of play style. Compare that to his brother, Luigi, and we see all the things that keep Luigi out of a higher power level. Luigi lacks a neutral as rounded out as Mario's. Instead, it's polarizing to the point where Luigi can have very hard times with certain characters (Mewtwo and campy Sheiks being the most notable). And if you look at Luigi's kit, you see why right away. First off, Luigi lacks the aerial mobility of his brother. His airspeed is notoriously bad to the point where his "danger zone" (basically the range of where the aerials will hit and force or force some reaction) with his kit of aerials is a lot more mitigated than Mario's even though Luigi's hitboxes themselves generally outrange Mario's. This lack of aerial mobility limits Luigi's aerials to shorter ranged pokes (which are generally less safe than Mario's aerials anyways due to Mario's ability to weave out of the opponents range or cross up shields) and fail to be as great of an approaching tool than Mario's, who's sh aerials are a great way to approach and condition opponents. Besides mobility, Luigi also lacks a reflector. So his fireballs, while fantastic and are vastly superior to Mario's own fireballs, must serve as his only mid range pressuring tool and as relief to incoming projectiles at the same time (in conjunction with shielding). When paired with poor mobility, Luigi becomes even more prone to being zoned out. This is partly the reason you'll see his down b pulled out in neutral. While very punishable if not used correctly, Luigi is able to close the distance and hit and opponent with a burst option if used at the right time. The last thing that should be brought up is Luigi's OoS compared to Mario. Simply put, obviously Mario's is a lot better at directly punishing shield pressure. A frame 3 invincible up b is hard to top by anyone. Luigi has a hard time directly punishing OoS in general if he doesn't perfect shield the hit. Even then, he doesn't have any frame 3 option at his disposal. Instead, he would either grab, jump cancel into an up smash or drop his shield to jab. If Luigi fails a perfect shield, it's usually much safer to just retreat and reset to neutral. This, again, leads to Luigi getting camped out. Because all he can do a lot of the time if he shields a hit without a perfect shield is reset to neutral...where he continues to get walled out. Now, it should be noted that while Mario overall is the stronger character in neutral, Luigi has the stronger presence in close range combat. SH aerials are finally within the "danger zone" I briefly mentioned earlier, Luigi's jab becomes a god tier move, you're within Luigi's accursed grab range, and now you have to fear Luigi's high damage output and kill power. But I guess what I'm trying to say is that Mario's other abilities in the neutral outweigh Luigi's pros in close range by a fair margin.
Now, after that needlessly long essay on the comparison of the Mario Bros. you'd probably expect me to say that Mario is easier to play because of his extended options compared to Luigi's more limited ones. Now, this is partly biased because I know a lot more about Luigi than any other character on the roster. But I'd call Luigi much easier to learn. The problem in calling top tiers easier because of their extended options negates the fact that you need to learn when, where and how to use those options. The fact that Mario has more options than Luigi in the neutral means that, to get to Mario's max potential in the neutral you need to study and know what his tools are and how to incorporate and link them into the grand scheme of his neutral of "how am I going to use this valuable asset to bring myself into the advantage state". Luigi requires less of that thinking because his tools are less in number and the versatility on some of his moves are very limited in a few cases (thinking of down b in particular). This general course of reasoning is why I imagine Sheik mains find it hard to be consistent. They have to stay aware of all their tools during a set, or they risk being punished hard in a combo because of Sheik's lighter weight and fast fall speed. Bowser in particular gets a special mention in this regard because as soon as Sheik misuses a tool or forgets to use one, Bowser takes about a 3rd of a stock until he's able to kill you with up throw to up air (I really don't know what the combo name is called nowadays, but I'm a fan of calling it the "Showtime").
One more thing: I'm not trying to say that Top tiers are the hardest characters in the world to pick up. In fact, some of them can be easily picked up as a pocket or secondary, like Cloud for example. But calling all of them easy mode is misleading in my opinion. They're definitely not Shulk levels of hard (God bless the brave souls who dedicate their time into that character), but they're certainly harder than a great bit of the roster just because of the depth of a lot of the characters. Regardless, I don't know if this hit the nail on the head, or if I'm completely off. This is just how I view things. I'd prefer to be corrected in places I was wrong in.