how do you figure?
this kinda ended up being longer than i intended, but whatever
the last paragraph is probably the least relevant if you want to skip it.
i kinda feel like melee's game mechanics in general feel more smooth
there's a lot more mobility with the larger dashdance windows, so you don't have to like... do a weird foxtrot thing to kind-of dashdance
wavelanding also adds mobility to some characters (especially for people like luigi and samus)
l-cancelling helps characters with high landing lag compete better, and kind of just lets you do more because you don't spend as much time unable to do anything
also, i think melee's faster speed in general along with more momentum being carried from dash jumps and stuff lends itself better to flowing. the higher hitstun also allows for more cool combos
not to mention smash 4's buffer can lead to moments where you're just like "what the hell? I didn't press down B but i still falcon kicked off the edge anyway" and that is absolutely something you should avoid in a game, especially a game that requires tight reflexes.
i feel like characters' landing lag should be universally reduced if l-cancelling is taken out because then it leaves those heavier characters with some pretty crappy air options
also because i really hate how little shieldstun is in smash 4. like, you really can't do any attack on shield without leaving yourself vulnerable to a grab or something (which i feel like reduced landing lag could help with a little)
and airdodges have a third of a second of landing lag which is super duper dumb to me (and leads back to the point of spending less time unable to do anything. melee's airdodge has landing lag, but it's a lot shorter. brawl's airdodge, i don't think has landing lag, but it might also have just a little)
and edgeguarding seems to get harder every game. from 64 to melee, you can sweetspot the edge (i don't think this is a bad thing, though. it takes some skill to hit the sweetspot and now it's actually possible to get back onto the stage from below).
from melee to brawl, the ledgegrab range is increased along with backwards grabbing (again, i don't think backwards grabbing is necessarily a bad thing, especially when the range for it is so small). most specials also autocancel to grab the ledge which means that the only way to edgeguard is to go out and hit the opponent, which is less effective because you can use as many airdodges as you want.
and now, from brawl to smash 4, airdodges have decreased endlag, so going offstage to edgeguard can be even harder. and now there's edge Annoying Orangeing, so edgehogging becomes useless (though edge Annoying Orangeing can be a way to edgeguard if you can safely manage it).