LineageOS TV is pretty good, just hook it into a non smart TV with HDMI CEC

Connect any TV to a laptop/desktop computer... running Linux, of course.

Am i wrong if I say: get a simple PC screen, or a beamer without android ?

I used to work in VFX, and for our big bright displays in the office we used digital signage displays.

I started using them at home in about 2018, after my nice medium budget sony TV died in a way that I couldn't repair.

I currently have an old HD NEC 48" display attached to an apple TV, and a freeview recorder for broadcast (although 98% of TV is done via apple TV)

Pros:

the screen is bright and adjustable. You can, if you wish fiddle with the colours and brightness

The screen is designed for 24/7 duty cycle, so is built like a fucking tank

It has all the HDMI you would ever need, plus displayport compute module ports (if that floats your boat) you can also get an ethernet remote control module (never tried it so it might be shit)

Second hand, they are dirt cheap. on ebay there are a couple of them in various sizes for <£400

If you don't have a compute module, the screen isn't going to spy on you.

Cons:

they are just screens. you will need speakers

They are built like tanks, so are heavy and thick (they are not the 15mm thick OLED jobbies)

Second hand, they generally don't come with stands or remotes

On ebay at least, they are generally pickup only.

In terms of driving it, Apple TV >> anything else I have used, apart from maybe a humax. Amazon firestick is frustratingly slow/unreliable. They also break after a year or so. Yes the apple TV is probably 5x the price, but the time to playing a show is about 7 seconds, from first pressing the remote to wake everything, to navigating to the show I want.

everything else I have used is horribly slow in comparison.

Disconnect it from the internet and connect a media player.

Whichever one does not connect to the internet

The one with the best looking picture at the store. Don't connect it to Internet and use your own streaming box (that you trust).

Really I think in store is the way to go. Some "low" and "mid" tvs look identical to me. Some "high end" are meh. Some other "low end" look great. I think it's a bit of a crapshoot. Not sure currently but Samsung QLED used to be rated well but I always thought LG OLED looked worlds better. I've always liked LG OLED although I've heard their firmware has gotten pretty predatorial...

I was browsing through the comments and thinking how insane it is that the answer basically appears to be “there isn’t any”. Most common advice seems to be either “buy an evil product and work against it” or “buy a close-enough something-else not-(yet)-affected”. Another instance of “enough bad choices make better choices no longer an available option”? Smh…

You can use a Sony Bravia connected to an Apple TV without connecting the Sony to the internet.

You could just use something like adguard to block DNS requests for telemetry endpoints.