Messi has made the right decision and I'm sure only he knows the answer to his choice, I think also if Messi enters the Saudi league then this league will be big because there are many star players who play and will meet other star players who play in the Saudi league especially CR7, I see Messi has chosen his final destination even at the top clubs in MLS.
Not only Al Hillah, even Barcelona, which hoped for Messi to return home, was not achieved, in the end, Messi chose MLS with Inter Miami, a bottom club, which maybe with Messi's arrival, it will color the league and improve their position even better.
I mean I understand that he wanted to be basically just doing something that would make sense for him alone, that's the thing that matters to him, that's the thing that makes the most sense for him. It is basically "his" club at this point, he will get share of the club and he will get share of the revenue, and all that.
Barcelona was a difficult choice because he wanted to be able to say that he is part of it and all that, and Saudi league would be like they paid him to play, just like any other team, maybe more money that's true but he would have no control at all, it would be just another owner paying his salary. He wanted some other type of deal, something that makes more sense, something that makes him feel like he is at the top table and not just a worker for someone.