Foreman had incredible power and threw hard strait punches. Being an idiot against Ali had nothing to do with his skills. If he had been methodical like Frazier did when Ali went was onthe ropes, he would have won.
The thread title is "Is Tyson Fury the GOAT" and not GOAT in his age group.
You thinking Frazier had no boxing skills is ridiculous. Rather than leading with his face, he bobbed and weaved. Ali said it was difficult to land a clean punch against him. His left hook is considered the best in HW history, he threw it from different angles and it won him a lot fights. After their first fight, Ali said, "All that talk about his left hook wasn't just talk".
I'm not convinced that the pre-first fight with Ali Frazier, couldn't have beaten Foreman. Frazier came in 10 pounds heavier for their first fight with Foreman and never had another great fight after his first with Ali.
There have always been big people but none in the U.S. have ever been competitive. As boxers get bigger, they gain power but lose hand speed and stamina. In the eras of great American champions, the point of diminishing returns was about 220-ish. Now that there are no longer great American HWs, the division has been taken over by European giants. Saying that Fury's size would given an advantage over the American HW greats is mere speculation. He has never fought anyone with similar skills to those guys.