It would be a big thing if they intend to become the mecca of world football, it is not impossible, but it takes a very long time, and keep in mind they will compete with Europe which can now be said to be the mecca of world football.
But the steps they are taking now have at least made them better known to many people. It doesn't have to be the mecca of world football, but they have to be able to show that the competition here is no less than the world's top leagues, such as the English League. They have shown that now and hope they can maintain it.
They do have the ambition to become the "mecca" of world football but it is not easy at all. They may have the money to attract the world attention but is money the only thing needed to make Saudi Arabia, the central of Global Football ? I do not think so.
In order to achieve this goal, it will require a significant time and investments. It will not be easy for any country (especially any Asian country) to come up and challenge Europe's dominance in the sport. Yes they have the intent, they are attracting not only high profile players but also coaches and investments into their domestic league. Saudi Professional League's growing reputation is a right step as how they are positioning themselves as a competitive football force.
I do not think they have "that" much money. Remember, they have like 3-4 teams that are doing fine right now, lets assume that they want to promote that to 10 teams, and they want to have 10 strong teams with stars, that would require them to spend hundreds of millions of dollars for each team, a total of a billion for the best teams for example, and that would mean billions of dollars every single year. That would not happen in a single day neither, that would require many years for that to happen, and in return? I get that they are rich and wealthy, but in return they would not make the same amount of money they are spending, they would lose billions on this, many billions.
You think they got rich by being stupid? They are rich because the yare not stupid, they are doing a marketing right now and that's fine, but they can't keep getting bigger and bigger, where they are now and what the yare spending now is enough, growing to 15+ billion expense type of level is useless for them.