if his contract expires in 2025 if he doesn't hurry up to be extended it will be difficult. because if the contract time is almost finished, enthusiasts will quickly offer attractive salary and contract facilities. just like Mbappe who will leave on a free transfer at the start of next season to Real Madrid. besides PSG, many English league clubs are interested. if it's a free transfer, Barcelona will definitely be interested too.
PSG could be a good option for Osimhen although I am not a fan of Ligue 1. But he will certainly be paid a huge salary.
Though Mbappe leaving the club will make the club far less attractive for other players and for fans in general. These days it is still fun to watch PSG play exactly because of Mbappe. The goals he scored in the Champions League were once more unbelievable. His speed is impressive, his quick movements and finishes.
Osimhen is not on the same level, but he would be good enough to win the Ligue 1 title.