Pretty much this. As I think they fought even tougher opposition: Fury's sheer size difference and Biev's ability to march you down with his insane power even hitting gloves (as happened in the 1st). Even Usyk - Dubois 2 has a case, though it seems now DD is a can because Usyk did easy work. Remember what he did to AJ.
As far as the Usyk part goes, I completely agree with the OP. Usyk's performances over super-heavyweights > Crawford's close decision over a faded, slow-footed Canelo. Bivol's performance was great too, but I do think Beterbiev is starting to fade with age.
Id like to have seen the Beterbiev v Bivol fights happen a few years earlier than they did but I suppose at least we did get to see them fight eventually .