MacOS is a good middle ground but not one I would personally use outside of a work machine.
I fail to see how it's a "middle ground" between the drawbacks you mentioned before.
When it comes to gaming, Mac OS is the absolute bottom of the barrel, compatibility is utterly atrocious. With Apple's insistence not to allow Vulkan drivers, they pulled the rug out of any leaps Mac OS could have made in that regard (like Linux did).
Apple also pulled the plug on any server capabilities Mac OS once had.
So, when it comes to gaming or server use, Mac OS would be my absolute last choice, not a middle ground.
Software choice is limited, but software quality is generally high and for some professions, the choice is flawless: when it comes to content creation, Apple's ecosystem is hard to beat.
Do you mean hardware encoding, because that's what's paywalled in Plex.
I personally migrated from a Jellyfin ecosystem to a Plex with Lifetime Pass one when building my current server - while both are highly capable media servers, Plex has, by far, the better clients.