> The irony is that you can still buy just a good screen with good connectivity options and basic controls, but the market is advertised as "display screens" intended for things like advertising or video walls.

That used to be an obvious possibility, but recent products in this category tend to run variants of Android/Tizen/webOS complete with Wi-Fi to support remote management. There are still a few relatively "dumb" models of commercial displays out there, but they seem to be a dying breed.