How is Kevin Garnett not the best power forward of all time?

The thing with Tim Duncan is that he had David Robinson right in the beginning of his career to help him learn. It's a clic example. Really, do you think Aaron Rodgers or Steve Young would have ever been as good without Brett Favre or Joe Montana to teach them? Same thing here? Kevin Garnett came in from high school to become a franchise player. He almost took down the Lakers by himself when his injured Timberwolves team met the Lakers in 04 playoffs. How is he not the GOAT of the PF position?