Because Lukaku has worked with Conte and they were successful with Inter Milan I think that is one of the reasons why Lukaku only wants to be transferred to Napoli. Overall his performance with Chelsea is not that good. Maybe Conte can put Lukaku in his best position. As far as I know Conte also wants Lukaku more than Osimhen. Napoli are in a difficult position. They have to sell Osimhen at a cheaper price if they want to get funding. No team wants to buy Osimhen for 120 million euros or 100 million euros if you look at his performance last season. CMIIW
I think Conte is not against working with Osimhen, but he does not need a player in the team who wants to leave. In addition, Conte has Kvaratskhelia and it seems that he counts on him the most. And Lukaku would be a good addition to his attack, they have worked before and I see how Conte knows how to motivate Lukaku, he plays differently with him. Perhaps nothing will change in Napoli, Osimhen will remain in the team, and they will continue to be the basis of Napoli's attack with Kvaratskhelia, this would also be very good, because these forwards are well-coordinated and such an attack has quite a lot of potential.
If it turns out that Osimhen fails to be released in the transfer market this time, Conte will definitely still include him in his plans at the club. But the question is whether if Osimhen fails to be released it will also make Napoli fail to bring in Lukaku. Because so far what I know is that Napoli will only buy Lukaku when they get funds from the sale of Osimhen. This quite makes me curious. Moreover, currently the transfer market will not last much longer. Because we are almost at the end of the transfer market.