Yes, I think Messi will return to Barcelona because for a player like Messi with the personality he got, that's important to play in a team where he can get the respect he can't get in PSG, sometimes there are many other things more important than the salary he can get, also I think he can get retired like a legend for this team instead of playing in Asian or American teams.
It may be true but Barcelona already has many good players, Barcelona shouldn't rely on Messi again. Barcelona is better to focus on young players. Young players will have a longer future, so it can guarantee for club future. While Messi is already 35 years old, he won't have a long time to play as a professional player. Also, Barcelona still has a financial problem, they may not be in an ideal condition to pay Messi's salary. Another consideration is no guarantee that Messi will play as expected when he returns to Barcelona. He may fail as C. Ronaldo for his return to Man United, I hope Messi better won't do the same thing.
This rumour was appears because recently Messi has been bring his family went Barcelona so that's why many people has speculate Messi will return to this team and other rumour too mentioned Barcelona really serious want to bought Messi even this summer Barcelona are willing to sell some of their players Raphinha, Franck Kessie, and Andreas Christensen
Besides that i have to agree with you that Messi is Barcelona past so they shouldn't rely on Messi anymore and Xavi has build this team with very solid without Messi and if this rumour is true i think there is no guarantee it will have positive impact for Barcelona conditions and with his current age i think Messi should be thinking to playing outside europe such as MLS or arabian league