Qwiss Isak is very good but he is not really in that very top tier of all time strikers
He doesn't have the drive unfortunately. Too comfortable at Newcastle, just like he was in Spain where he also stayed too long. He doesn't have the body for it either, but that's secondary. If you want to be top dog you need to push yourself and not settle for a medium club. He should do everything in his power to leave right now after the seasons he has had. Who the hell stays three years at Newcastle? Incredible player but he's never going to be anywhere near someone like Ibrahimovic, who backed himself everywhere every time and wasn't afraid to go to war with everyone to get what he wanted.
Gyökeres has that same fire in him despite having perhaps a little less natural talent than Isak, and it makes him the better striker.