That's a bit like asking to get a "smart" TV without the spyware / adware. Sure, you could pay more! But they can also just take both your money and that other money. What are you gonna do, buy a non-"smart" TV? :)
I recently bought a Samsung television, which came with a bunch of the smart nonsense. During the whole setup process I was thinking "I have made a mistake, I need to return this ASAP" but forced myself to continue clicking "no" through the setup screens.
After about 5 minutes of setting up (never once connected to Internet), it's pretty much exactly what I wanted: a display for broadcast TV and for HDMI inputs. A pretty good one, too. The only "tricky" part was getting it to remember the last channel/input at power-on instead of going to it's "home" screen, but that was just a setting in a menu somewhere, not particularly hard to find (though I'm the kind of person that does a depth-first-search through the entire menu tree just to see what all is there).
I think the key is never letting it get a taste of internet. No internet, no ads :) The internet-related things I do want to watch (like youtube, etc) are easily accomplished through the Linux PC I have connected.
These exist and are called "digital signage" - usually these things got far brighter and more durable panels, downside is they usually hover around 2x the price of an ad delivery device.
Plug in your old Chromecast 4k or Apple TV, that's it.
