The link has a ton of information.
Now, It is obvious that putting it completely offline is more safe. But, some people often use the TV’s to watch Netflix or something like that. Then they might forget that it is still connected to the internet when they are done watching.
Under Privacy Settings, there are options for Device Usage Data, Collect App and Over-the-Air Usage, and Interest-Based Ads. All are enabled by default, but you can disable them.



Sceptre was still offering some non-smart TVs that were quite cheap and work fine. They aren’t going to be super impressive in technical specs, but they work just fine. It might be worth considering a soundbar or speakers though, as that is one place you can feel the quality difference.
Most importantly, they aren’t available where I live.