MagnesD3 you are so stupid I have to call you out personally. YOU DON'T EVEN KNOW IF THE SWEETSPOTS ARE TOO GOOD. WHAT ARE YOU ARGUING ABOUT. DO YOU EVEN KNOW OTHER VALUES? Trajectory, growth, base, etc.
It is not just about the sweetspot. It's that the followups are not challenging or spontaneous, but rather DELIBERATE and SPECIFIC. It is about build orders and optimization based on designer's intent. This whole thread can be captured in Oracle's post. Inherently ****ty moves FORCE players to think about how they use their tools. There are exceptions, but if you follow the design of PM, there are no exceptions. Every move is deliberate and changed to fulfill not only a specific role, but even specialize in it. There are no reasons to learn tricky followups unless you are bored with the game. There are no reasons to learn tricky approaches unless you're a master of the matchup (WHICH IS IMPOSSIBLE WITH THE CAST NUMBER AND CONSTANT, TECH-DEMANDING CHANGES). This is what forced design is. It FORCES you to fight approaches in a strict RPS way instead of a creative, movement based way.
Forced design CAN be good. There are millions of games that are competitive from the get-go. For every person who says I am a melee nostalgia ***** and ignoring any of the design aspects of this thread: STFU.
Just read this. TL;DR SPAM YOUR ****ING MOVES GOOD
Do have some comments I'd like to make however. I don't have a ton of pro melee experience or whatnot, but as a game designer this is what goes through my head about this:
1) When there are really 3 types of actions in smash (Attacking, Defending, & Moving to break it down to the simplest parts), why is a slight focus on attack suddenly a bad thing? In all honesty if attack is stronger, it makes the other two seemingly more important in order to combat attack no? Movement and Defense need to be used more creatively / skillfully to counter attack, and possibly reverse momentum or reset situations, if not just start your own. Each being equal would boil down to each individual move vs each other move vs each situation vs each spacing and so on and so forth which would be a pain to consider. So instead, the design philosophy of "slight lean toward offense" means that each character should have the tools necessary to push their offensive momentum given the set-up (be it opportunity, spacing, aggression, what ever). What this really means though is that in practice, attack can be self-defeating as attacking by itself will leave the player open to counter-attack by smart players and lose/swap momentum in the match. To me, that seems reasonable as defense is needed to directly combat aggression and possibly switch the flow of the match in your favor, movement is needed for both offense and defense, and offense is ultimately needed to actually win a match as you do have to KO your opponent by hitting them in some manner (unless they happen to swan dive off the stage for you, but that is their fault).
2) Why intentionally design bad moves? You mention how lower tier characters in melee had to use creative spacing and movement for their moves to "work" seeing as well, usually the moves were bad and they needed the creativity. So, how about those characters with good moves that could also space them creatively with movement options? They're called the top/high tiers. This is a delicate balance sure, as some characters may just have bad movement and moves (See melee Bowser) or great movement and great moves (See 2.5 Sonic), the trick is to design the moves to work in tandem with the character's movement option (as I said above, movement is connected to offense and defense equally). The blanket term for "good" moves are more or less moves that could be good on anybody in my opinion: most Sex Kicks could probably work on any character due to the properties and do their job just fine, some characters would use it better than others but for the most part a Sex Kick is in general a good move as it both sets things up and can even finish foes. An attack like Link's Down Air is harder to grant to other characters as while a Sex Kick can set up other moves or opportunities, the Downward Sword is one that needs some sort of set-up or punish in order to be used more often than not, which luckily Link is suited to doing. Other moves like say, Jigglypuff's Sing however barely work with the character they're on to begin with as it can hardly set-up anything her other moves can't, and has nothing that really sets up into it. So what we got are really 3
* types of moves: Moves that can set up more moves or be linked from another move (Good), moves that only do one of those things (ok), and moves that don't really do either (bad). We should totally avoid the last one of course, as they usually do not serve any meaningful purpose for the character except for once in a blue moon shenanigans. So this leaves moves that set-up and can be linked to, and moves that do one or the other as the "acceptable" moves more or less.
*In terms of conventional attacks,some others like Lucas' Offense-Up and the like are a little more "odd" to categorize, but even then you could count it in the 2nd category as it sets-up his Smash Attacks.
A move like Fox's Nair could be considered "Ok" in all honesty as it's more a linking move than anything, while a move like Bair is "Good" in that it can be used to start, end, and extend a variety of moves to deal both damage, space and KO. What makes Nair a great move on Fox however is his mobility paired with a Linking move that links to so many other Good moves that can both link and finish maneuvers and restrict / create opportunities for the Fox player.
Charizard's Jab is an "Ok" move as it is a pop-up option to link to more juggles. His Bair is "Ok" in that it sends foes way behind him and generally gimps or kills. Fair is "Ok" in that it generally just kills or links generally just into itself. Nair is "Good" in that it can kill/position/link and so on. Charizard is incredibly fast for his size on the ground, which combined with his range (thanks to size again) gives him incredible coverage. Combine that with the ability to pretty much fly, Charizard could be argued to have incredible mobility.
So, why are Fox's moves better than Charizards? Charizard has maybe even better mobility than Fox in terms of raw movement (he can fly!) combined with range, but what he has is a bunch of linking moves and ending moves that are designed to go A > B > C / D, while Fox has fewer moves that strictly just "link/finish" and many more that can do both. Fox's maneuvers generally end go A/B/C > B/A/C/D > D/C/F. Fox's high mobility combined with the sheer amount of options he gets for successfully using his moves (either hitting normally or just spacing) allow him to be a dominant threat, while Charizard's options while effective, are ultimately limited through design to really only work when they go from A to B so to speak, at least when compared to a character like Fox.
This variety of options ties back to the first point again as Fox can then use these abilities both offensively and defensively to swing the momentum of a match in his favor thanks to his movement combined with the "Good"ness of his moves. This then leads to the depth you praised, however it also circles back to: not everybody can be like the top tiers with great movement and overall good moves.
Many characters are designed more on the Charizard end (don't mean to pick on him, hell I main him more or less, he's just the example, same with Fox as just an example of what Vro was saying) in that their options are more or less designed: Move A leads very well to move B, which can lead to C or D. This is because it is honestly just easier to fathom and design interactions like this while still then getting the desired result of things Fox can do, but it does not allow the sheer amount of things Fox can do in return. However for characters lacking mobility, this is a godsend more or less as they can then have really devastating options as once they do manage to get a hit in, they get to really reap rewards.
It is definitely a difficult task to balance a game of 30+ characters in the way you want, sure, but at least we have bases for how we'd like them to play as well as in general just stronger moves that work well with each character in order to offset the sheer power [Fox's] moveset provides. I agree that moves should have a little more to them to emphasize options, but I think it can wait until that becomes a priority as playstyles seem to be the focus now rather than super minute changes such as an inner hitbox of Zard's Fair sending slightly down to change his options from the move, as the move does it's purpose on top of Zard not having the entire melee metagame time of like, 12ish years to figure out all his quirks like the melee characters have? The game is subject to change for the better, and anything done can be un-done if it proves to not work out.
[thus concludes my very simplified take on the matter at 2:30 am during finals week]