Far too harsh on De Gea this season. De Gea has had as good a season as those two. De Gea could be more commanding, sure, but the biggest problem with De Gea vs his peak is that he was throwing in howlers every 5 games for the past few seasons. He's stopped doing that, Atalanta aside. He's not a big problem at all, on current form. If he starts throwing the ball into the net again like previous 1-2 seasons then yes he is a problem, but on current form he isn't.
Ederson is a good footballer but he doesn't have to do anything. He's faced less than 25 shots all season! That's the Man City system. Alisson is a superior keeper to Ederson in my opinion at all aspects of being a goalkeeper and could fit into any team. Alisson is the best in the league in my opinion, then Ederson or De Gea. But if De Gea gets back to his form of 5 years ago, then he's up there with Alisson.