I've been arguing against such powerscaling for years now. I'm not saying that's correct at all.
As i said potential =/= powerlevel.
Potential wise it absolutely is true imo.
They are literally the chosen ones, the Supreme Kings who would rule the world.
Powerlevel is as i said completely different.
Kuzan takes a dump on Katakuri, because (1) Kuzan has better fruit, fruit mastery & most likely better haki and (2) Katakuri never reached his full potential.
As simple as that, really.