It is undeniable that Ronaldo is the main attraction in Saudi Pro League, maybe they should look for a new star to replace Ronaldo in the future. With abundant financial power, Saudi can do anything to satisfy their desires, although we realize that it is not a guarantee of success. I think Saudi has done a thorough analysis to invest in football, they will definitely get results from the efforts that have been made. Everything takes time to process, what is clear is that Saudi shows a serious interest in developing their football talents.
Is that required now? Ronaldo has given the Saudi football as a whole and the Saudi Professional League the visibility that they lacked earlier. Now they just need to maintain that visibility. For that, they don't need to spend hundreds of millions of Euros every year on top players such as Kylian Mbappé or Julián Alvarez. At the moment they have good players such as Moussa Dembélé, Sadio Mané and Aleksandar Mitrović. IMO, that should be enough to maintain the momentum within the league.
Ronaldo gave them some attention, but he knew that it was not going to be sustainable. The only thing that made anyone sustainable is the money that Ronaldo got. All the buzz around him is more or less gone. Remember how huge everything was and how headlines were written about him in the Al Nasr jersey, but what is left of that. Al Nasr is behind, he isn't the best goal scorer anymore and the only thing that is stable is his income stream. Many great players after him have decided against going to there. Modric, Lewandowski, Messi (all won the best footballer award), Mbappe... I don't know but I think they were hoping for more.