So I’ve always wondered whether it wasn’t so much Ali wasn’t the same but rather the opposition had 3 years to develop ways to combat him. Obviously as a young man no one had seen his style so had not strategies to combat it. As an example, Ali would jab slightly open with his right down opening...
Hard to say isn’t it, I’m not disputing your overall statement, just the argument he would have been unbeatable. He didn’t pack and explosively hard punch and as his opponents got better you could argue he realised he couldn’t fight like he did v Williams for 15 rounds.
He lost to Frazier however still 29 years old, and in boxing terms that is still pretty young. When Ken Norton beat him, Ali was 31, even in the return 6 months later, Ali only won on a controversial split decision. When they fought a 3rd time with Ali now 34, again it was a close decision...