For now there is no team that can challenge PSG as far as the French ligue 1 is concerned because the gulf between PSG and the other teams is very wide but going into the next season this defeat to Chelsea has shown areas that PSG should improve on so that they can maintain this top form the coach has already stated after the game that they where going to review the game and look at areas where they got it wrong.
So far it's only madrid that has won the champions League back to back in this era so it will be difficult for PSG to replicate that
Ligue 1 has mostly never been a problem to PSG ever since they started dominating the league, they have their strength both financially and with the quality of their team and this has further continued to keep their morale, but this does. Not fo beyond the Ligue 1, even with the champions league they won, I still do not want to see them as been unstoppable or too formidable for other teams out there, untill they are able to replicate a fragment of Madrid's results at the champions league, for me they are not solid enough in the champions league but still tops in their Ligue 1.