Osimhen has now got a team that can make him more confident and make him play as a core player in the new team. Osimhen seems no longer needed as long as the new coach replaces him with Lukaku so he has to adjust to the new team, Osimhen needs a good performance to make a name for himself as a player that the team needs in a core position with a more aggressive physique when playing in matches, I doubt if Osimhen wants to go to the Saudi Pro League because there is still a chance to play in the team he is currently contracted with, hopefully Osimhen can play well and win League with success in 2024/2025.
Looking at the last time I saw him on a video at his new team, it appears like he's not finding it challenging back there and obviously liking where he's at currently and would do as much a s he can to staying there and further his career and making sure he's not going to have to really be under any form of pressure to get anything done as he would have probably elsewhere due to the expectations that would have been placed on him in the regards that he's sending as a to clas player going by his records so far. The lukaku as a replacement for osimhen doesn't seem to Napoli like a bad swap but with time most likely we would get to see and know if it was a good deal enough to be considered a perfect replacement but in the meantime lets hope for the best for them.
Osimhen is happy with the clubs he is with currently and that will boost up his performance because he will be playong with rest of mind and that will make him to be able to put up his best performance in the club. Unlike when he was sad in Napoli and that demoralized his passion for the club which affected his performance.
If you look at it from the other side, Lukaku is getting old and weak amd in no time he might decline in performance and that will still affect Napoli. Conte is pleased with Lukaku as a striker because he believes in his potentials as the man that's fit for the job but i would have preferred Osimhen because he is younger.