Industry also won't form because of Dutch disease. Who wants to build a factory in Saudi Arabia even if it weren't unstable? Everything just costs too much because of the oil - land, materials, labor.
Sovereign wealth funds also don't really solve the problem because 1) they attract corruption like flies on shit and 2) they're vulnerable to confiscation from foreign governments if they decide they don't like your face (e.g. Venezuelan gold in London).
I suspect it could be that there is no simple solution to this. Potentially you are just fucked if you're a poor unstable country with oil and theres nothing you can really do about it. No leader will save you and no policy will help.