D3's disadvantage is generally over exaggerated (well, except for his ledge getup and OOS options. Both are trash). His ability to land, while not great, is a lot better than most would think. Multijumps+ridiculous fast fall speed+scary aerial (bair) or command grab mixup means that he actually has a lot of ways to throw off anti-air pressure.
Also, despite the big body and fastfall speed, his weirdly low gravity helps him escape from true juggles more often than one would expect.
That all being said...his disadvantage is definitely still bad, but it's not some roaring dumpster fire like he's typically chalked up as having. That distinction would belong to both his neutral and on-stage advantage states. Those are both bottom 3 material, easy.
Super Dedede Jump, despite being a good recovery, is very easy to see coming, so anyone with a counter (
,
, and
especially) can punish the penguin king. Plus, even if King Dedede cancels the stomp part, unless he somehow hits a ledge, he's gonna get caught.
You know SDJ auto-snaps the ledge on the ascent, right? It also has no hitbox going upwards, so there's nothing that would trigger a counter in normal situations. D3 should almost never go beyond the ledge when recovering with up-b, unless he's praying that his spacing was perfect for an instant-stomp (which is incredibly lethal, granted, but stupidly difficult to space correctly and risky to attempt, as he has no super armor at that point
) or if he catches the opponent committing to something dumb (like charging a down smash mad early for a 2-frame).