Crocodile has no flashback needed yet he is top 10 villain and reach top 50 popular list.
Kaido has more screen time than crocodile and have flashback
What went wrong for kaido ?
Kaido was setup and hyped since Thriller Bark. Especially more so with his reveal and that intro post Dressrosa. Oda could bring back Kaido and make him more badass and redeemed like he did to Crocodile in future arcs, which I would love to see but I'm not that hopeful he will do it, especially after his flashback now too.
I found Crocodile very charismatic and cunning too, he didn't have to share screentime with a fucking awful, cringy, terrible, lame etc villain like Orochi and thus wasn't competing for screentime too. Ironically Crocodile introduced awakenings but didn't have the face the wrath of a "literal God" and thus Luffys awakening, the "new Joyboy", he has no idea how LUCKY he is especially considering how much helped Luffy at Impel Down and Marineford too ofc!
Its kind of a blessing that Oda hasn't brought back Croc now too because he'd probably ruin him too. Oda made Kaido seem way too strong, hyped up, epic, mysterious and blue balled us for 140ish chapters during his own fucking arc and made him share his arc with another Yonko.
In fact, its like how Kidd fans like me have been waiting since fucking SABAODY to see Kidd in action and get his own arc and seeing Law get SEVERAL arcs, a fully fleshed backstory, a novel IIRC, being a hononary and so on. He even admitted he exepcted Kidd to be the important one rather than Law, so either he's fucking rubbing it in/adding insult to injury or things really didn't go to his own plans.
Wano has been the Law show too bigtime. Even vs Big Mom, a lot of anti-Kidd people and there is a ridiculously disgusting amount of them in the OP community, have been slandering Kidd with his input vs Big Mom compared to Law and how Oda has handled him this arc.
I love Law a lot but Oda should have let him have a breather and sideline him somewhat at least this arc, give the guy a fucking break after Dressrosa lmao. Didn't he suffer enough?! I actually feared Oda is going to kill off Law and thats why he's given him so much screentime, development and such compared to Kidd, but by this logic, you could kinda argue the same for Sanji vs Zoro in that regard and ain't no way in hell Oda is killing off Sanji or even any Straw Hat for that matter too. We already had a "Straw Hat death" with Merry too.
I know I'm being bitter but I had so much hype, wonder and whatever for Kaido and I just feel Oda is either trolling us purposely or really dropped the ball fucking hard. People can tell me I set my expectations too high but when the absolute majority of the fanbase is calling the series peak fiction, the best/greatest/king of all the series out there and doing it every single chapter even and calling Oda as Goda and hyping the shit out stuff like Kaido themselves too, can you blame me for being hyped too?
Kaido deserved much better, sure hes really fucking durable, strong and even varied as a fighter but I feel Oda was lacking in creativity still with him too, both as a character and a fighter and I will always honestly/unapologetically say I am underwhelmed with how Oda has handled him and I'll die on that hill if I have to.