You have a bunch of weasel words there that are doing some heavy lifting: "majority", "actual" and "overwhelmingly".
It's not possible to run a functioning country (which SA undeniably is) without a large number of people who are at least somewhat competent, at least somewhat hardworking, and at least somewhat loyal to the country. You may be able to rely on cheap migrant workers for the hard physical labor, but not for the planning and administration that makes the whole thing work.
According to https://money.cnn.com/2016/10/20/news/saudi-government-worke..., 70% of employed Saudis work for the government, and according to their civil service minister, "many" of them don't even work an hour a day. If you think they're structured like any other country and I'm merely singling them out with "weasel words" we can't possibly have a discussion.
The oil money printer can hide a lot of problems. A small percentage of somewhat competent people aren't guaranteed to be able to provide for a huge number of useless freeloaders if the gravy train stops. Look at Venezuela for a somewhat similar situation.
It's not possible to run a functioning country (which SA undeniably is) without a large number of people who are at least somewhat competent, at least somewhat hardworking, and at least somewhat loyal to the country. You may be able to rely on cheap migrant workers for the hard physical labor, but not for the planning and administration that makes the whole thing work.