I don't think this will be the right decision because Chelsea is also in a downturn so if he doesn't get strong support from his teammates then Osimhen's performance will not develop and it will also not be good for his career.
I heard several teams want Osimhen, including PSG, so I think rumors of Osimhen's transfer will continue to grow in this transfer market and it is very likely that Osimhen will leave, especially if Napoli manages to get Lukaku.
However, maybe there will be hope that Osimhen can bring when he is at Chelsea, because now they also have a new coach who is expected to make Chelsea even better.
Oh yes, if we look at Lukaku when he played at Chelsea, he didn't play according to what was expected, apart from the injuries he faced, it seems like the style of play in the English Premier League, especially Chelsea, didn't suit him. Or he came at a time when Chelsea was not doing well, so that affected his performance.
Conte wants Lukaku to be in the squad, Napoli have to dig deep into their pockets, because Chelsea themselves will not let Lukaku go at a cheap price, especially since they also got Lukaku at a very high price at that time. Whether Napoli will try to fulfill the coach's wishes or not, what is clear is that they must first try to negotiate so that they can fulfill their coach's wishes.