This is why I bought a 'dumb' commercial signage display, never connected it to Wi-Fi, and feed it video from a Pi running Kodi through a hardware HDMI filter I built to strip the HDMI-CEC handshake because I don't trust the handshake. Took 6 months. The TV is now perfectly private and also I mostly watch the Pi's boot logs because configuring Kodi broke it.
Naive. Modern TVs ship with their own cellular modem to phone home even with no Wi-Fi. I read this. I cannot find the article again but I read it. I've wrapped the TV's mainboard in copper mesh to be safe. The picture is worse now but the picture was always a vector.
I solved this by not owning a TV and instead describing movies to myself from memory. Total privacy. Vizio knows nothing. Neither do I, I've gotten the plots wrong for years.