Smart TV manufacturers are relying on the ongoing revenue from their software side nowadays, so they’ll usually mandate setting up an internet connection as part of the device setup process, and then only give you the option to change networks instead of disabling it outright.

If you’re tech savvy, you can take measures against this, but it’s not going to be simple for most folks.

You also have to worry about ethernet-over-HDMI unintentionally exposing the TV to the wider internet.