Usyk vs. Beterbiev in 2023 would look exactly like Usyk vs. Gassiev in 2018. The only difference: Usyk could potentially stop Beterbiev. If he really wants to.
Beterviev would decimate Bellew. Bellew was never even in the top 10 best at cruiserweight. He was very lucky to win a belt.
With all due respect, I'm more impressed by Beterbiev than Usyk. He won all his 21 fights by KO. And the way he finished Smith Jr in 2 rounds, and how he destroyed Browne. I haven't seen it from Usyk. AJ couldn't land on Usyk. So his being very powerful doesn't make any difference. If Beterbiev and Usyk fought, I think Usyk wouldn't endure Artur's hard hits. Because Artur would be able to land on Ustk more that AJ could.