You can’t draw conclusions about Elliott’s ability by looking at what has happened at Villa. Emery is using him to score points with his directors. And even if Elliott has floundered, it’s no surprise after Slot parked him for an entire season.
Slot has effectively ruined Elliott’s career. He may not have been a world beater, but he was a young contributor with a higher ceiling than this. He’s gone from someone Klopp relied upon, to someone who hasn’t played PL football for more than 12 months for no reason at all.