I think the cool kids today buy commercial “displays” (used for things like advertising in retail areas). They don’t have smart functions. They don’t connect to the internet. There’s no tuner. You’d have to bring your own antenna, media player, HTPC, whatever to send it content, but it’s 100% under your control.
The other option is a computer display - there are pretty large ones that act the same (probably just a commercial display in a different box for a different market). The prices weren’t historically that high if you didn’t need absurdly high resolution and refresh rates (gamer stats - irrelevant for general tv watching).
I haven’t tracked any specific brands for years so can’t give a specific recommendation, but I’d suggest looking for second hand. If a store goes out of business their displays will be cheaper than anything you get directly from a distributor.
If that’s a dead end, you can still look at a bloated smart TV. Just don’t connect it to the internet, ever. Generally the same result as using a simple display, except the bundled remote will probably have a bunch of stupid buttons you’ll never use. My tv has a huge Netflix button and every time o accidentally press it I get a giant ad to buy Netflix 🙄