2025 Canelo for sure. Its not even about who’s the better fighter. 90s Foreman beats 70s Foreman. 70s Ali beats 60s Ali. Money May beats Pretty Boy. No ATG boxer is losing to their younger self unless they are in the shot phase, too much experience and knowledge for that to happen.
70s Foreman takes 90s Foreman's head off. 60s Ali dances around 70s Ali and wins decision Money May only beats Pretty boy on size alone, the footwork was faded.
All 3 would lose and it’d be only because of the skill and experience gap along with the advantage of knowing their younger self.