I think Lukaku is no longer a hidden striker as he has been seen performing in different leagues in his good and bad forms but we must admit the impact he has created in the teams he has played so far because he is not a total waste as a striker even though his stay at Chelsea he couldn't prove himself once again. Conte should be the better coach to use him very well knowing that he accepted to bring in Lukaku who is of age and who has lost form judging from his performance at his former club I believe his first appearance in the Napoli game where he scored the equalizer for Napoli who's that he will be useful for Conte in Napoli with the position he's playing there.
Conte wanted him instead of a younger Victor Osimhen that already knows the league very well therefore Lukaku has alot of presume on him to prove Conte right. It doesn't matter what he has done in the past, he has a task to make Napoli better and win their games. Conte is a very vocal coach and if Lukaka doesn't deliver him goals, he's going to begin to have problems with him. Conte has a history of falling out of love with his players. Napoli plays Cagliari for their next match and Lukaku needs to keep scoring for the manager to use him more. He doesn't have a good relationship in his previous clubs and the fans know this therefore he needs to make them happy to get them supporting him
1. The reason why coaches chose a player to work with us not just because of proficiency and their personal inclinations. They also consider acceptability of the player to both the management and fans. In the context of discussion, due to the fall out of Osimhen and the Napoli team, Lukaku seem more acceptable both in the management side and the fans side.
Also, you need understand that the Osimhen fee and salary should be way higher than Lukaku and honestly, Lukaku can do virtually all that Osimhen can do.