There is nothing evil about playing in the Saudi Professional League. It still the same football and thesame rules. But you will agree that the quality of the game in SPL is far below what we see in European Leagues. And if a player want to win world recognized personal awards he won't have the oppurtunty to win it in the Gulf League. The bottom line is that most players will not move SPL if they have offers from clubs in Europe. The only motivating factor will be money. That is why most players who move there are those who has passed thier prime. Victor Osimhen will consider moving to SPL if he wants to make money because he still has many offers from top European clubs.
You're right, players moving to the SPL have either leave their marks in european football or are money driven. Osimhen was close to joining the SPL because he was frustrated at Napoli. The deal with Chelsea had just collapsed and there was no offer on the table aside Al Ahli, which later collapsed and he moved to Galatasaray at the eleventh hour. With his blazing form and interests from top european clubs, a move to the SPL right now is not possible, maybe later in his career. I believe he wants to play at the highest level and win trophies.