They dont only play Messi (and he carries them alot of the time going to midfield), they have tried everything, they played him with Aguero, Higauin, Aguero, Dybala, Di Maria, at times with atleast 4 of them same time as him. They have zero organisation is the main issue, you cant go out there as a team but play as individuals.
Biglia, Mascherano, Banega etc are good enough to get better results then they do right now. Even if they are top heavy team. Most of the choices they can make in 11 is fine for me except for fullbacks and goalie IMO.