For the past year I had fun messing around with Docker containers, Moonlight/Sunshine and HW acceleration; so much so that I've ended up building a Gamestream server from scratch!
The basic underlying idea is to allow the followings:
Share a single server (possibly headless but doesn't have to be) with multiple users
by creating virtual HW accelerated desktops
whilst keeping remote mouse, keyboard and controllers completely separated
with low latency
It's still rough around the edges, and it needs more testing from the community; if you want to check it out, here you can read the docs and here's the Github repo.