Saudi Arabia is one of the richest countries in the world, so the idea of creating your own cryptocurrency for banking operations is a great idea.
I think Saudi Arabia is in deep trouble. The future is going away from oil. Solar and Wind Power are growing at exponential rate. Adding to that the US is becoming energy independent (fracking).
Saudi Arabia is running at deficit spending. The scuttlebutt a few years ago was that SA needed $100+ / gallon oil prices in order to run a budge surplus. Since then SA has been in a very costly war in Yemen.
They're bleeding funds, selling assets. SA may be wealthy, but as with China, they're heading for difficult times.