Correct, but it is a two-way benefit. No doubt, Cristiano Ronaldo accepted the offer to play for the Saudi Arabian league for money. If they had offered him anything less, he wouldn't even think of playing there. However, it is also that the Saudi Premier League needs him to play for their league. This will give a lot more popularity to this league when you know the big names are playing there. Anyway, all this is possible because the Saudis have a lot of money to bring football home. They are also the hosts for the 2034 FIFA World Cup. 
Please don't generalize everything. How do you know that Ronaldo chose Al Nassr only for money? What I know is that Ronaldo was not happy at either Manchester United or Juventus. He was not getting the respect that he deserved, and he was not being involved in important decisions related to the team. There is no denying here that the money offered by Al Nassr was huge. But that would have been the case in case he moved to any other major European club.