Saudi diversification from oil is a fantasy. The culture is medieval from the POV of the rest of the world, and the hostile climate is only getting worse.
In 2018 "only" 43% of UAE's exports were zero-value-add extracted oil & gas. 11-12% was "Gold, Diamonds, Precious Metals"(?). The rest is pretty evenly split between very different industries - value-added chemicals, electronics, cars, metals, industrial machines, and textiles.
Overall, UAE pulls in a higher % of their foreign currency from non-oil-and-gas economic activity than Saudi does, but still leans heavily on it for 40-60% of their exports. Saudi exports ~20% more oil & gas than UAE on a nominal total USD basis. However, UAE's total exports are 30-40% higher than Saudi's on a total USD basis. So UAE sells less oil, more other stuff.
If I had to pick, I'd definitely rather be in Dubai's position than Saudi's. I've also lived in both places, and I'd definitely say that Dubai appeared to have a more diverse economy and drew from a deeper talent pool (mostly immigrant-based, though).
I'm not sure if Saudi Arabia can reproduce the success. The entirety of Arabian peninsula is pretty much immune to cultural development, but Dubai got a pass because they were the first ones in that area to try building a normal healthy economy, meanwhile whatever Saudis do, they have to compete with Dubai which is already highly developed.
My point being, why would people invest in Saudi Arabia if they can invest in Dubai.
Saudi is at the mercy of it's leader and little else. The culture isn't generally medieval but the Al Saud certainly can be.