It's the bigger picture that Birdy is pointing out. Messi is all about the project and having a competitive team. That means surrounding himself with teammates that make him comfortable these days. Don't forget Jorge Messi cited leaving PSG coz of the project
So if he come back to Barcelona, it would have been conditional to his amigos staying. Something we can't do right now because of financial constraints and diminishing returns on a sporting level.
At the point in his career that he can go and do whatever the fuck he wants, and request whoever the fuck he wants to play with him. I'm sure these guys met up and whatsapped eachother to discuss the three options
a) staying at Barca together
b) finally going to Miami together
c) the unexpected option of going Saudi, get super paid and smoke Shisha together.
In the end Miami won out and it is probably the best choice for the lifestyle these guys want, and that they just don't want to go through the physical demands and pressure for top European football anymore. Well, you can just see that looking at Busquets, he looks as giddy as a kid in a candy shop. Only thing someone needs to tell him that in America, kids in a candy shop get shot.
Anyways, apparantly Inter Miami have agreed a deal with Iniesta. And you know what that means.