Chelsea, at present, is not a good place to develop talented players. Choosing a good club is very important for every talented player. Choosing a good club is a factor for a player to play in the Champions League. In my opinion, Osimen would prefer to choose PSG over Chelsea if he has good team management considerations. Luis Enrique is undoubtedly a good coach.But aside from these considerations, talented players make financial offers without the chance to play in the Champions League. It creates a very hostile environment.
PSG isn't the best place to develop talent either and it's also import to know and understand that osimhen isn't at the level of developing his talent rather he's at the level of advancing his talent so I don't think he is looking for a place where he can get to develop his talent, a place for advancement is exactly where he wants and than england has been his dream and not France so PSG may look good but not what he has wanted.
His counterpart mbappe is leaving because he's understand that he's career cannot be advanced in PSG been a team he has played for in a long while so I see no reason why a player osinmhen at his level with his caliber will be going their to develope or advance his skill meanwhile some one who's likend to him of almost similar status is leaving for the same purpose of advancement of their career so isn't actually not making sense for osimhen to find himself in PSG except he gets enticed by the pay offer but for the purpose of career advancement england remains a better option if he eventually gets an opportunity there.
Developing a talent in PSG is very much possible because actually that was the place mbappe got his talent to the peak of his development and now wanting to advance, but then it actually took some long while so a player going to PSG for the purpose of career development will need to have some kind of patience aswell less he may leave before that talent is developed because it's literally going to look like its slow.