Rings are an extremely convenient abstraction when it comes to talking about operations that trap (so, basically, the whole foundation that security is built on

Rings are an extremely convenient abstraction when it comes to talking about operations that trap (so, basically, the whole foundation that security is built on). It's perfectly reasonable to keep talking about it even if the origins are no longer used (or usable at all, in long mode). It even makes sense with the NX bit, thanks to the control register that lets ring 0 bypass write protection. To be clear, the only thing I'm disagreeing with here is your last paragraph.