This was the original architecture of Multics BTW -- the world just consisted of a single address space of segments (pages) plus a capability-based address space; a higher level construct gave you a named structure for a group of segments.

A similar approach has been taken with HP's interesting memristor-based "Machine"

There's a lot of interesting stuff in Organick's book on Multics, not all of which was implemented, unfortunately. And a lot of really good stuff was tossed overboard when fitting Unix into a PDP-7 (a lot of overwrought bad stuff was jettisoned too -- don't get the wrong idea!).