It has always been very easy to create separate users on Linux and certainly for tasks where you need to switch between contexts.

Linux is a unix, so has always been multi-user and sharing any data between processes is facilitated in all manner of ways. So context could be shared over files or unix-domain sockets or shared memory or tcp or udp sockets or via message passing or … a bunch of other ways. That has been the case since 1996 or so when I started using it certainly.