I do not think that PSG will be all that bad just because they are losing Messi, he wasn't the only person that made them good and won't be the reason why they may become bad. First of all, they barely won the title anyway, and they lost UCL as well, so it wasn't some epic season for them neither, and that's why I wouldn't say that it matters all that much. Secondly, I feel like we should be focusing on who they are going to get, if they get someone better than they will be fine. They still have 24 year old Mbappe, Marquinhos, Hakimi, Mendes, Donnaruma, Kimpembe. '
These are all great players they can win UCL with, and they just need to find players for other positions instead. Neymar is still there officially but I am expecting him to leave as well, that should be easy enough to see.
In fact, the coming and going of a player is a normal thing that happens to all football clubs. that means, it's not only Messi who left, it could also be other players including Mbappe. it's just that this time what we are discussing is Messi, so Messi's departure will not have a big effect on the team as a whole. at least, there is still Mbape that can be relied on. so, PSG management only needs to find a partner for Mbappe next season. after all, PSG is a club that has abundant finances. to sign a star player, it's fine for them. let's see which players will be on PSG's hunting list in the transfer market later. after all, PSG has also not confirmed to recruit a manager who will coach them next season. although there are several candidates, none of them has been confirmed to handle this French league giants team.
As for Neymar, until now he is still with PSG. we'll see how the future will be. the rest, whoever will become PSG coach later. you can be sure, this one team remains the strongest in Ligue 1. For the Champions League, this depends on which players the management will bring in. not only for Mbappe's partners, but they have to strengthen the midfield. at least, PSG have to bring in some potential newcomers in this season's transfer window.