Is there any difference in getting your oil money paid in Saudi than to getting it paid in Paris, Manchester or Newcastle?
It's bad for football if elite players get bought out before they're irrelevant to top flight. If Xavi never became our SD/manager and we had a Pep, Arteta, De Zerbi where our football weren't neutered then I'd be in the camp Messi's return wouldn't be beneficial. Messi's the only player Xavi can't force gimpball onto, and they both know it. Of course Messi got a little disillusioned, rightfully so, with Barca's project for few years before he had to go to PSG, again rightfully so the same playing in Paris where first time he had ignorant fans booing him. But World Cup prep and part Galtier this season he's clearly showed he can dominate and moreso than any current Barca player when motivated.
He'll have no motivation in SA, sure he'll still give 70% effort there, to earn 1b/yearly performing bear wage but I also have no doubt especially after winning WC and another Bdor perhaps, going immediately from being crowned undisputed GOAT to near total irrelevance. I would hope his 'greed' for recognition and attention, rightfully so, trumps his "greed" for irrelevant-to-him money. He sees the sad state Barca are in, and if he can help revive the ship while Xavi's still here, well I still wouldn't consider him a saint for it but it would only further his legacy. He needs a compelling challenge and his home Barca is the only place that can give him that.