I do something similar with an LG TV, but my point was you don't really have many good options if you want a TV that doesn't at least try to track you and the average consumer doesn't really know it's happening nor how to avoid it. Also, using a set top box on an external input is not free from tracking as most smart TVs use screengrabs and automatic content identification to figure out what you're watching even then. You can theoretically opt out deep in the settings, but it's often made confusing to do so via dark patterns.

As for network connections yeah my TV is on a firewalled VLAN that I can selectively let out if I want to do a software update, but my personal conspiracy theory is that we're gonna see cellular modems hidden in TVs at some point to pipe data back. GM got caught doing exactly that in their cars without telling anybody not long ago and I think it's already mostly forgotten. Even without that, most consumers want to plug their TV into the net anyway to watch Netflix, probably not realizing it's a poison pill.

I'm certainly not anti-"smart" appliances and I think they can add a lot of value if done well, but in response to the OP I'm saying that it's getting to the point that you're forced into it by the market regardless of your preferences. General consumers and legislators don't seem to care enough to stop bad practices via market or regulatory forces.

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).