Comment by Miraste

From personal experience, Roku OS TVs (TCL mostly) have a very good non-internet user experience, with a dedicated mode for being a dumb display. WebOS (LG) is decent. Tizen (Samsung) ones are okay, although the one I have is from before they started putting ads in the menus so I don’t know if there are placeholders. None of them have disabled any features or nagged me, or tried to sneakily connect to the internet. Google/Android/whatever-it’s-called-this-year TV (Sony) might not even be usable without internet, I’m not sure. It’s also terrible.

Generally, firmware updates on modern TVs are used for creating bugs and performance problems, rather than fixing them. They also add advertisements. Don’t ever connect it to the internet, and it’ll be fine.