I think Oda tried an half-measure with Kaido and it didn't work.
He didn't make him a brilliant, charismatic villain like Doflamingo or Crocodile.
Neither did he make him a relatable, human antagonist like Katakuri.
Kaido was a pure brute without intelligence or depth.
And tbh he lacked ambition too.
Seems like Oda tried to go with the
pure beast route for him, which is fair, but he didn't elaborate it fully, which means an
half-measure.
I mean, making the main villain of an entire saga (that started
10 years ago) rely on strenght only to catch the reader attention is already a risk, on top of that Oda tried to throw in some gags and quirks that simply didn't work with the character.
If a beast is what you want to depict just go all the way.
Kaido should've been a real beast.
A vile creature, not even a human.
Something you can't reason with.
As readers, we should've felt chills on our spines every time he was on panel, like the Minotaur did the first time he appeared:
Again, Kaido should've been a beast with almost no dialogue and almost no brain.
An invincible creature that is just that... a creature. With very little cognitive ability.
Like the Chimera.
Or Nemea's Lion.
Or Creta's Bull.
No place for remorse and shit like that, just a famelic beast striving for destruction and blood.
In my opinion, this was the right path for Kaido.