His recovery is not the worst, I can name plenty of characters with worse recoveries: Link, Ganon, Olimar [depends on the stage], Ivysaur [same boat as Olimar] and Ness. There is no way Bowser is worse at recovering than Link or "PK Touch me to Gimp or you have two whole seconds to stop me some other way".
This is so easy to argue against it's ridiculous.
Dude, nobody cares about horizontal recovery if you have good DI, which EVERY GOOD PLAYER has. There is literally no character in this game who has any issues with horizontal recovery as long as you DI correctly. That is the only kind of recovery Bowser is "good" at. He fails HORRIBLY at everything else that ACTUALLY matters.
What actually matters in this game for recovering:
1. Vertical distance
2. Having a REASONABLE airdodge
3. Having access to some form of safe priority (safe as in low lag and good disjoint plus decent anti-juggle properties)
4. Being able to land on stage safely
5. Ledge options
6. Momentum mixup options
Bowser is basically the worst character in the game at virtually all the categories I mentioned. What Bowser's recovery does is it basically moves STRAIGHT TOWARDS YOU ASKING TO BE *****. No other recovery in the game is nearly this helpless. Except for maybe Kirby's recovery in the G&W matchup.
I know you mentioned DK's recovery as a comparison. DK's Up-B is completely different from Bowser. Firstoff it actually goes far and fast enough to escape some traps unlike Bowser's. Second it actually has existent priority. Lastly it has the option of landing onstage virtually laglessly, while Bowser's does not. Oh and it gets more vertical distance and it OUTLASTS LEDGE INVINCIBILITY. Now while DK does still actually have many of Bowser's problems in recovering safely, they are MUCH less severe. And he has a momentum brake option. DK's recovery >>>>>> Bowser's.
Link's recovery is leagues better than Bowser's. Sure you can argue he hates getting gimped more, but he can actually prevent it better than Bowser. He has projectiles, a decent N-air/F-air, and even though his vertical distance might not look impressive, it is better than Bowser's, and that matters MUCH MORE than what little horizontal distance Bowser gains. A Link player who DIs well doesn't have to helplessly fly into your **** zone. He can bat you away, and *gasp* has something that resembles vertical mixup options unlike Bowser.
Ganon's recovery is kinda the same story as Link's, minus the projectiles. His recovery is worse than Link's, but still significantly less punishable than Bowser's.
Olimar is floaty and has a good midair jump and airdodge. And his tether gets good vertical reach AND he has access to immediate and lagless Super Armor. His recovery is easily much safer than Bowser's.
You obviously have not played any good Nesses if you think Ness has a worse recovery than Bowser. I play ViceGrip, one of the best Ness players in the country. Yeah, Ness's recovery is iffy, but he gets a lot more vertical distance than Bowser. His F-air is gay to challenge while he's recovering, and he can Magnet Stall to mix up his momentum. A good Ness player who knows how to recover in reverse is actually annoyingly hard to gimp. At any rate his options are clearly much more diverse than Bowser's for successfully keeping his opponent away from him.
Ivysaur I guess has a comparably bad recovery to Bowser's, but it's actually debatable who has the worse recovery. Ivysaur has a kinda low commitment projectile and of course gets more vertical distance than Bowser. Plus Bowser's airdodge is fail.
Bowser's not that bad. First of all there are characters with worse recoveries than Bowser (it's still pretty bad) but like most people with recoveries like that, he just has to recover high. He is pretty easy to juggle and pretty slow but he has some things going for him. First of all, Bowser really packs a punch. Strong kill power and a lot of damage (klaw does 18% if fresh). He has an extremely good OOS option (UpB) which is definitely one of the best in the game and does a very good amount of damage (10-12 if SS). He has a good grab game with his GR tricks. His ftilt is an amazing spacing tool. It's fast and has a lot of range. He's also heavy as **** (I think heaviest in the game). He is a good defensive character but when an opponent gets in he's basically screwed. Bowser also gets very little rep. I only know of 2 good Bowser players: Vex and KingKong and I've seen both of their Bowser's. They're really good. I think he's in a good spot right now. Give or take.
I'll go back to my point that basically he's trying to compete with Ivysaur for how awful his recovery actually is against someone who knows how to edgeguard.
Bowser's strengths are okay, except with the kind of safety he actually has on stage, he requires twice the survivability of Snake, when in actuality he's a very fragile character who cannot afford to take many hits. When Bowser gets hit, he tends to get comboed, and don't tell me that damage is just damage. Once Bowser is offstage and over 100%, if you have good reaction time, he's basically dead. He can do nothing to get back on his feet reliably when he's over 100% and forced to use his recovery. His ledge options basically don't exist at that point, and his options to escape juggles never really existed in the first place. When you put this into perspective, Bowser's huge weight is actually working
against his survivability by making him easily comboed and thus limiting his ability to successfully implement his ledge options, which he NEEDS in order to recover successfully.
Honestly there are a decent number of characters that have cool stuff to do onstage. But Bowser is clearly at a unique disadvantage when compared to all the other interesting characters in this game who have by far better survivability than he does. No living to 180% does not immediately count as good survivability. With that I rest my case.
Actually almost forgot. Ike's recovery is actually really really awful but underexploited. You don't have to perfectly edgehog it to **** it. Since he doesn't sweetspot the edge with Up-B, you can basically do the Melee gimp tactic on Ike where you grab the ledge, and use your invincibility frames to hit him out of his Up-B. And of course gimping Ike's SideB is basically a matter of seeing it and hovering in front of it.