Is it even possible to buy a tv nowadays that doesn’t have this crap?
Never connect a smart TV to your WiFi, disable WiFi, connect an Android TV box via HDMI and use that. Debloat, root, or run a custom ROM on that box. Then run SmartTube, Jellyfin, Pi-hole, etc. to bring ad-free sanity to your living room. Obviously a dumb TV is best. But this is your best alternative, if you already have a “smart” TV.
Sceptre still makes dumb TVs (that are actually consumer TVs, not overpriced digital signage displays).
Yes. You have to go and look for business display panels, e. g. those used for menus in restaurants, fast food chains, display stands etc.
And be ready to pay. And while the panels aren’t so bad don’t necessarily expect enthusiast-consumer grade features like local dimming zones and whatnot.
Better bet is to just buy the best TV regardless of the crap and never hook it up to the Internet. And amid reports that some even hook into open WiFi signals, maybe open the damn thing and unhook/cut the WiFi antennas.
Then use whatever you like.