The truth is, they have to work harder to win the champions league. On the face of it, Mbappe is forced to assume the offensive power alone. In this case, it is bad for PSG that the offensive zone, which weakened without Messi and Neymar, is left alone in Mbappe. They have Dembele next to Mbappe, but they also need a finishing striker like Haaland in the future.
This season is the time for Mbappe and Dembele to work hard on PSG's front line and several other players must also be able to work hard on their respective lines so that PSG can compete better in the group stage in the Champions League and in Ligue 1 such as usually. Because it is too late for PSG to hope for a finishing striker like Haaland in their front line, so PSG can only hope that the existing players can work hard during this season.
Getting a striker like Haaland would be a miracle for PSG anyway. Things are not looking good at PSG at the moment. Especially after losing their important players, Mbappe will not be next year, so they will have to hold on tighter this year. This year may be better for PSG, of course, who will add to their squad during the interim transfer period, all will be shaped accordingly.
In this season, I think PSG only needs to stay focused only in Ligue 1 because it will only be useless if PSG focuses also in the Champions League. After all, even if PSG still prioritizes the Champions League then still, the end result PSG will still fail to advance further in the Champions League this season. Therefore, instead of dividing its focus with the Champion League which in reality still has no chance, it would be better for PSG to make its good performance consistent in Ligue 1. At least, if PSG can still focus on Ligue 1, then PSG still has a guarantee to win the trophy this season rather than not at all.