Apart from the fact that Napoli wants to make some profits from selling Victor Osimhen but they should also know that Osimhen helped them to win the Scudetto in the 2022/2023 season and he's currently the club's most valuable player of which he deserves to be an expensive signing but since no club have been able to meet the demand of Napoli to sign him, Osimhen should still remain with the club.
I think Napoli just want to be ignored Osimhen because is not well stand like before since the time him came back from the Nigeria striker and got some injuries, if not everyone knows that Osimhen is a great players even thought is not doing well or perform better for Napoli again, I think in the years back Osimhen help Napoli win some leagues but even some of the fans didn't remember that they only try to blame the guy.
As for Lukaku, i don't think he can play the role of Victor Osimhen because we have seen him play for Inter Milan on loan in 2022 and also moved to Roma on loan in 2023 and I believe that if he has made good contributions to those teams one among them would have considered signing him to their team. I'm not saying that he is not a good player, he is but he's just an average player and cannot be too relied on to deliver for Napoli. However, he can't handle the role of Victor Osimhen.
For the lukaku, is fine Napoli can sign him but even after they finally signed into the team I don't think he can play the pattern of Osimhen and get experience reach Osimhen is Napoli, I know that in his currently team is made so much contributions but that does not means it can deliver that positive changes immediately for Napoli, he have to learn the role of victor Osimhen for him to get defferences of experiences.