The funny thing is that it was the subsidies that did this. Once it is no longer possible to keep subsidizing stuff, the situation can quickly turn. It is wealth without a solid foundation.
I don't know for how long they will be able to continue like this. The oil prices are not high enough to meet the budgetary expenses, and the sovereign wealth fund is shrinking in size ever since 2011. On top of that, they are waging a very expensive war in Yemen, which is costing a lot in terms of finances and manpower. If the Aramco IPO flops, then that will be the end of Saudi Arabia as an united monarchy.
Are they really that desperate for cash that everything rests on the IPO? Well, regardless, they can only keep pushing back the inevitable for so long. Just like when the dues finally catch up when you keep on borrowing money (Hello Puerto Rico), spending earnings irresponsibly will catch up when you run out of money.
What would be KSA without oil? Dubai at least have tourism to fall back on, can you imagine Western women going on a beach in KSA without having to wear a burkini? Even the "build it and they will come" policy don't seem to work. KSA has built large malls but so far tourists are not flocking there, like they would go to Dubai to shop during vacations.