I think Messi is trying to be realistic now and he didn't want to make a blunder that would put him in the same situation a second time. We all know that he left Barcelona because Barcelona's financial situation was in turmoil and Barcelona has no option other than having to sell Messi. So if Messi has worries about returning to Barcelona, I think it is a reasonable thought because even though 2 years have passed, Barcelona still has problems with their finances and Messi knows the problem perfectly.
Barcelona's financial condition does not allow Messi to be sent home. Actually Messi wants to return to Barcelona but on the other hand he doesn't want Barcelona players to lower salaries and sell young players so he chooses not to return to Barcelona. I think this has chosen the right one for Messi, because even if he returns to Barcelona he will not be like before especially with the condition that Barcelona is still in a transition period.
Failure more than five times in a row in the Champions League before moving to Paris proves that Barcelona must have regeneration. Lionel Messi was the good old days for us but Barcelona live for today and tomorrow let talented young players like Gavi and Pedri, Frankie de Jong become the backbone of Barcelona.