The fact Fultz's team won only 9 games in college while Lonzo doubled the win total of UCLA from the year before.
Wins and Losses matter. And Fultz is not a player that affects winning and losing. While Lonzo is a player who does.
That's not his fault if he had a worst team completely. If you compare Ball team against Fultz player by player UCLA will be better. He was the best player in college with the worst team even facing triple teams especially against UCLA in their match which he outplayed Ball.