Surely people can just buy used dumb-TVs?

I have a much older LCD TV(admittedly Samsung, but it was a gift) from around 2011, no smart features, but it's still perfectly good and works with all my HDMI devices. If there are millions ditching their dumb-TVs for Telescreens, that must mean that there are plenty of dumb-TVs for sale on eBay and Craigslist.

But those eventually break and the supply dries up. Not all panels are equal, so good luck finding a decent 2019 era 4k HDR monitor in 2029 or 2034. If the LCD and control board don't give up, you'll be swapping LEDs, caps and FETs sooner or later. And that's assuming HDMI will not be superseded.

So, let's hope that free-market thing actually works and at some point a "dumb display" product will be available again.

That’s what I did, bought a dumb Samsung TV in 2016 off new egg.