His first season wasn't all that great. It was decent. What he had going for him was that it was his debut season for Barca and that is why people got hyped and hopeful about him. Issue now is is that he has not improved since then, possibly even regressed.
Not only decent. Good at defending, great at getting 1st on the ball - which is crucial for a team that wants to press high
PLUS good doing forward, not trickery of Dest and stuff, but good straight-forward overlapping runs at RB
Plus decent passing, even assists
This season he has been a shadow of himself from last season.
Who is responsible for his regress, I dunno