Fair enough, I tend to agree as I am impressed every time I watch him.
I think the overall point is that, no player, no matter how good, can improve a team to massive levels. Barca need to improve to beat RM to the title, and that will only come with becoming a better TEAM. Signing technically gifted, smart players like Olmo helps that but he is not gonna transform them himself. You need to build a team with good chemistry.
All the stuff about fees, wages, whether Barca can afford him, his injury record, I am not abreast with as much. But purely as a footballer, I think he could definitely play for Barca. However, for Barca to be an elite team, he wouldn't be one of the best four players in the side imo. Like how Busquets or Alves were brilliant but they still had Xavi, Messi and Iniesta who were a level or two up on even them, who were already great players in their own right.
This Barca team is obviously nowhere near that level, but the same principle applies. Olmo for me can be a good supplementary player in a top team.