Will we never know who the best heavyweight ever is due to ducking and fights not being made?

Styles will always make fights: Let me explain in a clear way-'Smoking' Joe Frazier was the first man to give Ali a loss as a professional and in the other two fights gave him extremely tough fights the last one was according to Muhammad Ali the closest to death he had ever been. Now look at how Frazier fared against 'Big' George Foreman in their first match 'Smoking' Joe was down more times than Foreman was in his entire career before the fight was stopped in the second after one shot literally lifter his entire body off the canvas! Now look at how Ali knocked out Foreman in 8 rounds , this is only one of countless examples