Thanks to the choices by their rulers, Saudi/UAE citizens therefore have a much much higher standard of living and global opportunities than Iranians.
You assume the people are happy with this "arrangement"?
KSA itself cannot even trust its military so much that it wants US protection both from external threats and also internal threats.
Look at the military hardware and military budget of KSA and they still have US bases on their soil and are now begging for "security guarantee" from the US for their Al-Saud regime.
Puppets like Gulfie rulers are disrespected by even their own people as most people have something called honour.