I don’t think anybody has ever said that comfortable on the ball is the only important quality. Lindelof has been defending good this season so I don’t really understand what or who you’re aiming at.
Also wondering what some posters are expecting from the defence. That they will completely shut down Messi, Suarez and Coutinho? Well, United were close; Barcelona had very few chances and it took an own goal for them to score.
Lindelof is not the type that does spectacular things, no last ditch tackles, no yellow cards, no aggressive headers, but instead relying on anticipation and positioning and he’s being a clean defender. He is very boringly doing his job. Sometimes it would be good if he was more aggressive, but there are also advantages with his clean and boring way of playing.