MLS can't offer money like SPL. If Messi's after money he'll sign a mega contract with Al Ahli. He's played in Argentina Spain & America so if he wants new experiences he'll leave Inter Miami. Messi's got options to stay in Inter Miami or go to SPL.
Yeah, that was the reason why he preferred Miami, and he will stay there for a while longer I am sure. It depends on what he wants to do after he retires, like if he wants to go into coaching or not, if he doesn't want that neither, he could literally live his entire life in Miami. Considering he is still scoring like crazy, that means he could just renew his contract there and get as much money as possible and just play until he retires, and then retire and live there as a retired rich person.
Miami is a great place to live if you are wealthy, and he is. Just because his contract is ending, doesn't mean he needs to move to another team, he could just keep getting paid by Miami, and he is earning a lot there too, not like he is working for a few million, people act as if Saudis offer a lot, and Miami offers nothing, but Miami offers a lot of money too, just because it's less than what Saudis offer, doesn't mean it's nothing, it's still a lot of money.