I agree that Osimhen is a quality player, but his value is so expensive that some of Europe's top teams are reluctant to spend much money on him. Chelsea could try to bring in Osimhen in the next transfer window if Osimhen is ready to leave Napoli. But if that happens then I think Napoli will not be able to compete closely in Serie A.
Napoli have changed and their performance is no longer the same as last season. I wouldn't consider Napoli as one of the title contenders this season if they didn't finish second during the first half of the season, so for me Milan and Inter would likely be the two best favorites to win it.
Napoli not on good position for selling Victor Osimhen on expensive price depend their player not productive or top performed such as last season, I doubt with Chelsea want to pay above 200 million euro based on bid offer from Napoli last window transfer opening. Have bad performance in this season, Napoli on difficult position keep hold their player Victor Osimhen exactly after getting problem when Victor Osimhen failed with penalty kick and Napoli social media TikTok account upload joke video.
But problem with Napoli want to reduce of transfer fees or not depend most expensive bid offer can't acceptable by any Europe teams exactly Chelsea is the only one serious teams for signing Victor Osimhen.