How much any of that would help a boxer, I don't know but I would think it could help a boxer. You know, in those superstar sports events there are football players who'll military 300-400 pounds then they'll have a joe Frazier who'll barely get up 160. I think there was another boxer in that competition but if weights didn't help the physical aspect of athletics, I don't think any of them would do it. Boxing, for whatever reason was never like other sports. Joe Frazier would have bullied any football player in the ring also, I think that maybe strength would give diminishing returns after a point in boxing.
As far as punching, I've never seen much correlation between strength and punching power, some of the greatest punchers are physically not that strong,(Arguello,Hearns) and some of them are, all builds have punchers so no seeming relation there. And the difference between someone who can bench more, what does that mean in the ring? He can push you off maybe but thats not the objective. I asked a guy who I knew benched way more than me to get in a shoving match with me, he pushed me off fairly easily but it wasn't anything dramatic, I suppose in some situations that sort of strength is useful but I'll never really think Ali was stronger than some of the guys he outmuscled, I know he was strong but part of it was his will and know how and also his stamina. Wrestling with Big George sapped George and he wasn't very strong by the end of that fight.
It's 2025 though and I'm sure the euros use weight plenty.