PSG are in a transitional phase. I would never call them "a mediocre squad", as I was saying they have a very interesting team, a great manager who knows how to work with young players, and if they give him and the players enough time they may actually make it. It doesn't always work, I remember 20 years ago Arsenal had a beautiful team with a great mix of young and experienced players but unfortunately they never won the Champions League.
You're right. It is totally strange if there are people who say PSG is a mediocre team/squad. Everyone knows that PSG is one of big teams since few years ago. Even, this team ever has Mbappe, Messi, and Neymar together in their squad. Nowadays, they still have many top players in their squad. Donnarumma, Marquinhos, Achraf Hakimi, Lucas Hernández, Khvicha Kvaratskhelia, and Ousmane Dembélé are some of the great players in the world. It is just nonsense if people say they are mediocre. They were just unlucky that they often failed to win UCL in the previous seasons.