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.