Stop buying smart TVs. Companies will stop making them if consumers stop buying them and creating a market for them. Look for commercial digital signage displays. You can find dumb TVs with nice screens or ones that just run a stock Android.
If this trend became widespread enough to have an effect on these companies profits I would bet money the vendors would just go the legal route and crack down on it. All these LLM providers do retain logs of your sessions and these vendors would easily be able to subpoena those records. Once they start dragging people into court and mass filing cease and desist orders that's going to end it.
People say that while forgetting to mention that you will spend multiples more money for a lower quality viewing experience. Oh, sure, it might be 4K but it won’t have HDR and the like.
Take the subsidized TV and don’t let it anywhere near a network connection. Throw an Apple TV in front of it for streaming.
For myself, I buy the smart TV and then just never connect it to the internet. Mostly because commercial digital signage is either way more expensive or is worse technology (and also more expensive).