Disadvantage in general is a lot more varied than advantage. When I say this, I mean generally your character is going to be pushing towards the same goal to kill your opponent (bowjow wants to hit kart in all his MUs, etc) while disadvantage's best options are determined by tool interaction. In some MUs, flip kick is that unpunishable escape button. In others, like Rosa, it is risky. Vs marth, going offstage is probably not a great idea, vs Sonic it can save your stock. etc etc.
Of course, your advantage varies based on your opponents disadvantage options... but generally its whether or not your tool works, not a total change.
Or, using Ike as an example, stage choice can profoundly change your disadvantage options. Quick draw is pretty great at battlefield, kinda meh at FD.
Then you have Witch Time, Cloud's Dair, Quick Attack... moves that you decide, during disadvantage, 'if I hit this I am immediately in advantage'. Pretty damn useful.
Anyways, this was just what came to mind when we talk about disadvantage. Your tools vary a lot based on MU. Quick Attack is really great vs Fox because you can suddenly combo or gimp him. Vs giant hitboxes, however, it is pretty damn difficult to not get hit.
Disadvantage is probably where Megaman fails the most, since his neutral is deadly and advantage, while not quickly deadly, keeps racking damage, and can be a quick kill if uair or bair gimps come into play. But his recovery is so meh. Vs someone like Corrin, this isn't so bad (though fsmash landing traps are painful) but vs Bayonetta, the nair wall can basically not be avoided if she plays it right.
In general, we talk about active frames, but when Bayonetta comes up, it is seldom mentioned that she can choose to just have constant active frames, unlike anyone else (except Mario >.>). This is something that is a huuuuge problem for a lot of the cast, especially when recovering. Or, relevant to disadvantage discussion, when they are trying to use airdodges to avoid traps.
Can bayonetta confirm from an extended nair? I think ABK works?