You don't attach the television to the network; the Apple TV or similar device IS attached to the network to function, but the TV itself is disconnected. This is what I presently do.
This article focuses on the sets but don’t fool yourself; every streaming device and every app on those devices is capturing as much telemetry as possible and selling it
I have even heard of some WiFi enabled sets which will surreptitiously connect to any open WiFi and phone home. They can detect programming that they display.
