For me, Jellyfin makes my smart TV (running webOS) tolerable. It turns the TV into the appliance it should have been from the start, without ads, AI assistants, or silly apps.
It wasn’t a single point of failure for a device. It was a single point of failure for the whole media ecosystem.
My Sony TVs all work without an internet connection, so I'd guess nothing?
There is also HDMI over-radio but I don't know its limits (range, bandwidth, latency).
I do wish I could just buy a dumb tv that just did TV things… but it’s simple to just use an Apple TV and never connect it. Or if I absolutely must to set it up or because there is a bug. Connect it via Ethernet briefly.
Better for privacy too.