Before Saudi Pro League teams spent much money for signing star player have did early by Chinese Super League teams and they pay bigger salary for many star player from European teams. But difference with Chinese Primer League teams because Saudi Pro League teams pay more higher salary until with how much money get by Karim Benzema over 200 million euro each season. Brings player have won Ballon d'Or its not really bad for Saudi Pro League team but most of them have been over age but will make their competition keep exciting for few years later.
The trend changed in the 1990s and early 2000s if veteran European league players who played in Asian leagues would choose Japan, Australia, then the trend changed to Chinese, Qatar, Indian leagues, now to the Saudi Arabian league, which has a small schedule but high pay.
I think this is just a matter of business so that the Arab League will be known by big names like Ronaldo, Benzema and even later Kante so that the advertisements will increase and Saudi Arabia will promote their league more openly. They pay the salaries of expensive players, that doesn't matter to them because when these star players advertise Saudi Arabia's domestic products, they will also benefit.
Saudi Arabia has planning become host FIFA World Cup 2030 and seems they want invest more with their teams football and bring star player make them easy later how to be host country for FIFA World Cup.
Yes, there is a point. Maybe Saudi Arabia wants to realize the 2030 vision with football as a soft diplomacy as well as a campaign for bidding on the 2030 world cup. It's cool, step by step, Saudi Arabia is now cooler.