Last I checked Osimhen is still in Europe. He plays for Galatasaray in Turkey and he's performing very well there. He's among the top scorers in the league and he's on course to help them win the league for them. He's not in Europe's top 5 leagues but he's still in Europe and still has a contract with Napoli.
I think it's a good thing his market value dropped so it will be easier for the team to sign him. Chelsea are feeling the consequences of not signing Osimhen last summer. I belive other top clubs will go for Osimhen or even Chelsea might go back for him.
Osimhen's release clause has already decreased a lot as a part of his contract extension with Napoli. His price dropped so much not caused by how bad he played. It's to ensure his clause has sense price, and he can leave anytime.
I saw some top clubs such as Arsenal, MU or even Chelsea strongly linked to him. However, there's no concrete development about which club has contacted his agent to buy him out. I hope Chelsea will contact his agent, then sign him asap .