I don’t think Messi will play in Europe for any other club but Barcelona. I guess it’s possible he may finish his career in the US or back to Argentina but I definitely don’t see him at any other European club.
Don't judge too early, there is still enough time for him to play on the other European clubs before he retires. I don't think he will retire very soon, and I also believe he still has the desire to try playing on the other European clubs like what CR7 has done. Even finally Messi may be back in Argentina, he should consider playing on the other clubs in Europe first.
I think probably only Man City & PSG can afford to pay the obscenely high wages that Messi earns. If he was to move somewhere else in Europe then he would have to join one of those two or agree to take a wage cut, possibly.
Though PSG is very rich club. But i don't think PSG can afford to pay Messi with such a high price now. Because they already have a lot of higher value player. Samples of the weekly salaries of some of the players of PSG -
Neymar - 700 thousand Euro
K Mbappe - 306 thousand Euro
E Cavani - 355 thousand Euro
T Silva - 305 thousand Euro
So, I don't think PSG will take Messi to their team with such huge money. So, I think, Man City is only able to give this huge money to Messi.