If the room is small enough room with the seating closet enough to the screen, a large computer monitor could do the job pretty well. You’d have to be fine with doing all input switching and audio control on a receiver or only ever use a single device as the input.
These days that’s through a box the cable company provides that plugs into the HDMI more often than anything else. If you happen to have actual towers in range maybe you can actually plug an antenna into the antenna port but that’s what TV Tuner cards that you plug into your Jellyfin/Plex box are for. Basically for folks looking for a dumb TV chances are they have no need for any of the actual TV features except for maybe the remote