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.
PSG will really be a better team if they are able to get a sharp striker like Haaland but how's that going to be possible when he's doing well with Manchester city and they were winners of the EPL and the champions League last season do you think Manchester city will be willing to let him join another club? I guess the answer is no. PSG should work things out with Mbappe probably work on improving his pay and getting more players that will be willing to player team work game instead of playing individual football because that's the number one problem affecting the performance of the team. There are possible of PSG keeping Mbappe next season even though he will be leaving as a free agent, once they are able to convince him to sign another contract and Real Madrid didn't come up with another offer since Real Madrid coach sounds so convincing about not looking for a replacement for Benzema again I think Mbappe wouldn't want to go to Saudi Arabia at his age since he's looking at winning the champions League and becoming the world best player since Messi and Ronaldo is off the competition now.