Turkey, never having relied on oil, still maintains economic viability without it, and to a lesser degree, so does Egypt, but neither will ever enter the inner economic ring.
Without oil, Iran is going to backslide enormously, and can no longer support anything close to its present standard of living.
Arabia without oil, or even without sufficient oil revenue, will implode. When the money dwindles, the foreign workers will go home. Saudi Arabia will be like a large resort, where the guests wake up without electricity, without hotel staff, and without any means of leaving.
I doubt we will see become unimportant in our lifetimes.
One Hundred years ago, they were guardsmen, wandering in the desert. One Hundred years from now, they will again be guardsmen, wandering in the desert. All of their wealth comes through the talents of others.
Without oil, Iran is going to backslide enormously
In my opinion, if Iran was lifted of the oppressive burden it lives under, it would flourish again, not unlike the economic miracle the Israelis created, in a barren land.
Thank you for considering an alternative point of view.