In my opinion, he should study and see about players who join Paris Saint Germain, indeed if we talk about money, Paris Saint Germain can pay him more than any other club. However, if we talk about career, I would not include Paris Saint Germain as a club that can make a player's career better. Let's see what happened to Mbappe after joining Paris Saint Germain. Indeed, he got many privileges, but he couldn't get anything special in his career, even though players would definitely want that.
Chelsea is not very good at the moment, so it is quite risky for Osimhen, Manchester United is also the same, but Manchester United is slightly better than Chelsea. If there is another club that is better and interested in him, I think he should consider that. The reason is that the situation of a club sometimes also influences a player's performance, unless the player can be at a very good level of stability, that might actually be what can take the club in an even better direction. But I haven't seen that from Osimhen.
I am more interested when Osimhem joins the English league compared to other leagues because if he is able to maintain the best playing form then in the English league it will be easier for him to achieve the best career. Chelsea is not at all a good place for him to come to now because the club's condition is very unstable and vice versa with Man United, but compared to Chelsea Man United is much better for Osimhem. If there were other clubs interested, maybe I would agree that he would be better off playing there, but so far not many clubs are willing to pay Osimhem a high price.
If players prioritize money then PSG is the place because there they can get everything like Mbappe, but talking about individual careers it is completely difficult for them to achieve this because PSG is only able to dominate the local league. If a player wants to have the best career then he must consider joining a certain club because if they are wrong they will actually bury their dreams of achieving the best career.