In my opinion, Barcelona is the strongest candidate to be able to win La Liga next season because it managed to keep Messi and also even managed to bring in a number of star players even though on a free transfer .
So what I assume will happen is that they are going to try to bag one superstar, which was said to be Mbappe but that is looking more like not going to happen but it could be someone else, then they will sell like maybe 5-6 players and use that to get 2-3 much better players and roll the dice this season, with all the money they will make next season, they will have 2-3 better players next off-season and suddenly with one bad season they can go back to being the best.