It seems like Osimhen is really going to Saudi Arabia... There was a recent update that Al-Hilal managed to convince him. I think this is really bad for his career. He is still young. Of course he will make lots of money but he would be less attractive to big teams when he returns to Europe. 
He's making one of the biggest mistakes of his career. If Osimhen had stayed in Turkey he might not have earned a lot of money but at least he would have continued to play in Europe. He is a very talented footballer, he is still young. Why would you want to go to Arabia when he is good enough to play for many teams in the Premier League?
If you are 35 years old and you want to earn some more money before your career is over, yes Arabia would be a very logical league, but if you go there at your age, your chances of playing for quality European teams again are very low