This Barcelona squad will need at least 2 more years to get in shape and in the situation to be on the top tier teams in Europe. But at the moment, they are a lower A-tier team I have to say.
But I have to admire Xavi with how well he has done with the huge duty on his shoulders. Even at a time, Barca weren't even top 10. But now they are 5th placed and the influence of him on the squad is visible. I'd say that give this team time, and Xavi some more time, and Barcelona will turn around.
Xavi's work methods are respected, but I don't think they are relevant for modern football. Firstly, no one will give a coach 2 years to experiment. The result is needed here and now and at the moment Barcelona is pretty bad with this - it has already been eliminated from the Champions League, the Spanish Super Cup and the Spanish Cup. A difficult play-off with Napoli is ahead. Secondly, the result is needed in order to retain good players and attract new stars. Top players prefer to play in existing top clubs and not to bet on promising ones.