I find this very irritating. Very frequently I come across posts saying that playing in the Saudi Professional League is evil and the players do that just because of money. I never saw such posts when he was representing Charleroi or Napoli. Playing for European clubs is some sort of charity and playing in the Saudi league is immoral? What sort of logic is this? Playing football is similar to any other profession. Osimhen chose the European clubs because the salary was higher. Else he would have stayed in the Nigeria Premier Football League. And he wants to move to Al Ahli, because his salary will increase further.
The Saudi Pro League isn't evil like you claim to have read in many posts but when it comes to quality of football, it's surely rated behind any of the top five leagues in Europe which is why people tends to frown at young talented footballers moving to the Saudi league instead of staying back in Europe and winning competing for trophies.
Victor Osimhen is still young but at this time of his career, I don't think he has much to prove again as he's already proven to be a world class striker so if he gets a lucrative offer to join the Saudi Pro League, then I don't find anything wrong with such move.