There are lots of challenges with a server+client architecture like jellyfin for emulation that disincentive people from doing it, like handling multiple instances, peripherals connectivity, etc.

There are a few ways to get close but with various pros and cons:

1. A compromise is having something like a NAS manage the data and metadata that multiple emulators can connect to e.g. 1 NAS + 3 PCs running Batocera with their own peripherals. This is the simplest option.
2. A headless server running an OS like Windows or maybe even Steam OS that a client can connect to, but you're limited to one client at a time. Many ways to set this up, for example https://github.com/Steam-Headless/docker-steam-headless
3. You could have a server running multiple vms with some OS like batocera, one per client. I do not think sharing GPU is feasible so software rendering only. You need to setup peripherals somehow for each client to each vm. Sounds complicated but plausible.

These options are all off the top of my head. I'm very curious what ideas other people share.