Hmm, so should we call this sort of thing a "Ponzi Scheme" or a "money laundering scheme"? That is given that Softbank is a way to recycle the Saudi Billions while other schemes involve Russia oligarchs or Chinese money itching to leave it's homeland?
Saudi Arabia's only serious pressing concern economically, is building a non-oil-based, sustainable economy before the oil growth era stagnates or reverses course. They have rapid population growth (50% in 15 years), the clock is ticking against their ability to sustain a future with 50 or 60 million people.
It's not enough to just replace oil in the equation as it is today for their economy, they have to figure out how to do it for twice as many people. They need to figure out how to build out a $1.5 trillion non-oil economy within 30 or 40 years.