Obligatory:Ederson’s reflexes and athleticism are absolutely incredible. Coupled with strength with the ball at his feet. He’s an above average goalkeeper.
The biggest knock against him is his positioning. He has absolutely no clue where he is relative to his goal. Those reflexes and leaping ability mostly make up for it. This has lead to some truly spectacular saves on shots a correctly placed keeper would routinely catch or comfortably parry. He will not age well as his explosiveness diminishes and reaction times increase.
The other piece holding him back is his decision making, and that’s what let him down here. He was caught in absolute no-man’s land and almost totally flat footed. I think that’s why Dembélé pulled the trigger. He looked up and saw Ederson unprepared for a shot. He took a bad one but Ederson had no time to set and react.