The Osimhen situation isn't really that complicated in the sense that it's all about the money and disagreement. Not like it's that unheard of, we have seen it happen many times in all over the world in many different sports. If a player wants to leave, and the team doesn't want to sell for cheap, there are arguments, player just sits out, and eventually it happens for some price or another.
Sometimes club gives up and gives the player away for cheap, but sometimes the club knows that it's going to happen anyways so he just waits for it to happen easily so they end up with something easy and not really worry about it. That is the best case for the current situation and nothing bigger happens for the long term. Osimhen leaving is best for all of them.
Napoli and Osimhen are no longer able to work with each other and Napoli need money while Osimhen needs a club where he can show his best as player career is too short and Osimhen should not waste golden years in his career for nothing at small clubs.
Players like Osimhen surely need money but having chances of playing and competing for big titles are important things with a player too. Osimhen must consider what he needs most in remaining years of his career and has to make his decision determinantly. If he wants to play for big clubs and get chances of playing in Champions League and compete for big titles or at least get experience in such big competitions, he must put salary demand at a lower position in his priority.