My parents are getting a new tv, and are asking for recommendation. I think all I can influence is the brand/model (not realistic to propose rpi and more complex systems). I instinctively avoid google/android and lean towards anything else open source, so probably LG WebOS.. But I had bad luck searching for more detailed comparisons. Maybe you have experience or opinions?
If I'm not mistaken, many smart TVs tend to take multiple screenshots per second and send it back to base with other methods if wifi or ethernet aren't available, although I gotta research a little more on that.
So even then, don't connect it to a PC, you're just waiving your privacy rights