That's a myth. When Wilt went to the Sixers he gladly cut down on his offense to help win championships. When he first came into the league, his owner demanded that Wilt score a lot of points for the benefit of league publicity. What was he, Wilt, supposed to do? Nobody regular had ever shot 50% from the floor before Wilt came into the league. Nobody could stop him one on one...not even Russell. And the fact was even though the Celtics had superior teams to Wilt's teams before the Sixers, several of his pre-Sixer teams came close to dethroning the Celtics in the semis. If Wilt had started his career with West and Baylor at the beginning of the decade, the history of the sixties would have been a lot different.
I grew up watching Wilt v. Russell. As individual players Wilt was unquestionably the dominant one. But the strategy was always to let Wilt try to win on his own. It always worked.