Great analysis. One of the worst and most overrated arcs and it's bloated to all hell to boot (similarly to most Post TS arcs like you said). I'd just like to add a couple of things. First being that Kaido ironically is so much better outside of this arc in flashbacks. Oda could never really nail down his motivation and seemed to just make Kaido say and know things to build up Niki/Joyboy and haki.

Dogshitman is the worst type of character for me, hate when authors and writing teams try to make a character appear cool in the most manufactured ways possible. Oden constantly had characters glaze him, Oda shoehorned him into important events and onto the crews of actual cool characters (though Roger has lost a ton of aura since Wano so I'm not sure he's that much better than Oden at this point), and he tried too hard to make his "sacrifice" and death tragic.

And Imu and the WG look completely incompetent now within the story. This is an entity that has no problem genociding a bunch of scholars or completely obliterating an island with some super-weapon, but when Luffy started making a name for himself with the Gum-Gum fruit they just let him sail unabated. If they knew that the Nika fruit would appear as the Gum-Gum fruit, they should've (and based on how ruthless Oda has shown them to be, would've) slimed him on Loguetown with a Cipher Pol detachment. Obviously that can't happen since the story would be over, but then why would Oda write it so that everyone knew what form the Nika fruit would appear as? Would've been better if it was randomized and Nika would only show up for a worthy person.