Ali would make Joyce look like he was drunk. he would cut him to ribbons. Cleveland Williams was 6'2 and 230 lbs..I think. not the biggest guy..but how big is Joyce? Size doesn't mean ****. Joyce was built for an easy pay day for Ali. Ali by tko by round 6.
The difference is that Ali was the giant back then... He fought the likes of Patterson, Liston and Frazier for God's sake... Usyk has much more in common with Mike Tyson than Ali.
And he also fought hard hitting monsters like Foreman, who btw is more durable and a harder puncher than Joshua. Liston wasn't small. He was 6'1 215lbs with incredibly long arms and an unusally strong build. He wasn't weak. He would ragdoll Joshua. Usyk hasn't faced nearly the level of competition than Ali did at heavyweight. Guys like Lyle are more dangerous than Chisora for example. Doesn't matter if Chisora is heavier.