Just don't connect it to the internet and use an Apple TV instead.
The difference between an Android TV launcher that's designed give people what they want, and the baroque monstrosity that results when Google tries to extract every fraction of a cent of advertising revenue that it can is startling. My TV just became an appliance that does exactly what I want, no less and no more, instead of a cacophony of distractions and diversions trying to convince me to do things I don't want to do.
The Apple TV is the only thing connected, and it will auto turn the TV on/off by itself(thanks HDCP).
So I guess someone could go really far out of their way to make the Smart TV parts work again, it doesn't seem very likely.
We use Plex almost exclusively, it provides the Live TV.