Yes, we are. I wouldn't say re-inventing, though. Hypervisors are effectively an optimization of microkernels: modern ISAs (e.g. x86-64) have special instructions to make "hypercalls" faster than plain-old context switches, so any modern implementation of a microkernel would be forced by practicality to act as a hypervisor.
Though, there's another advantage that comes specifically from thinking of each process as a separate "machine": each process gets to participate fully as an Internet peer, with its own unique, public-routable IPv6 address.
Though, there's another advantage that comes specifically from thinking of each process as a separate "machine": each process gets to participate fully as an Internet peer, with its own unique, public-routable IPv6 address.