Fun fact: I actually tried to connect to the internet when I got it. This, of course, prompted it to show me a bunch of ads on the "home screen". This didn't really stop me, after all, I never look at that page and it has direct access to what I watch (broadcast TV and Prime).

But the prime experience was so horrendous, everything lagged like hell that I just couldn't keep using it. So I went ahead and did a full reset, which got rid of the ads, and I connected my ISP's provided box. I didn't try the broadcast tv performance, since I didn't have an antenna cable on hand.

Now, I don't know about other markets, but here in France basically everybody gets their provider's box, even if it's only for public TV. It gets you nice affordances such as a generally better picture and the ability to pause/get back in time. Those boxen usually come with the usual streaming clients, too.

So basically, there's no need to connect your TV directly, even if you're not paranoid.

Sure, the TV can do its screen grabbing, but since it isn't connected to anything, the only possible issue is for its buffer to fill up and somehow break. This hasn't happened yet on my specific TCL.

However, I do realize that my ISP can also know what I'm watching and sell this information to "partners". I've yet to see any ads on their box, but I wouldn't bet the house this will never change. So I agree with your last point, this will probably continue going downhill until we either see the public waking up (on which I don't count at all) or some regulatory action (which seems somewhat non-nil, especially here in the EU – but they seem to have bigger fish to fry, such as listening in on my chats themselves).