Interesting. As you say though, oil is boom & bust. There's no getting away from the fact that the vast majority of the gulfs revenue still comes from Oil, which is in decline (especially if western governenments get their way with banning cars from city centres & the continued push for electric vehicles being more widespread). The worlds dependency on oil is slowly being wained. If someone manages to crack the whole hydrogen fuel cell thing & is able to mass produce them at similar prices to petroleum based vehicles then they could be in serious trouble.
Are the gulf states doing enough to get a contingency in place if it does go bust? I'm not so sure.
I suppose only time will be the ultimate test & everything else is speculation at this point, but personally I can't see this particular (albeit vast) bubble lasting a whole lot longer.
Oil and Gas (less so) is boom and bust, but its very cyclical. It used to be about a 7 year curve from bust towards the end of the boom because the majors will wait before committing to going ahead with big projects, in my experience at least.
However, the Middle East, particularly Saudi is less boom and bust. I think the North Sea break even is around $80 per barrel, however Saudi is way down as the cost for recovery is a lot less, probably 10-12. Our field in Iraq for example is around $8. Saudi Aramco is the biggest operator in the world by a long way for good reasons
Undeniably, the Middle East's main revenues come from Oil and Gas, however, despite the West looking to reduce the reliance on fossil fuels, the desires for Oil aren't reducing that much because of the uses in plastics etc.
Saudi probably has around 100 years of Oil reserves, but due to improved technologies for recovery, this may be a conservative estimate. In addition, new fields are still being found.
Do the Middle East countries have contingency in place? I'd say so. Saudi, Qatar, UAE have all invested heavily overseas in major companies and the likes of Saudi have recognised that there is a need to change