Obviously surrounding cast matters, but some fans don't want to admit that the gulf in performance between Mac and Tua right now is absurdly large and likely bigger than the difference in receiving talent around them. It's not like Tua's performing at a slightly higher level, he's been the best QB in football by a mile and Mac has been the 15th-22nd best QB in football.
As for what Tua does that makes him a better fit for NFL offenses, he's a much better anticipatory passer and is more precise with his ball location. He puts the ball in places that maximize YAC consistently and more often than Mac.