In Defense of Dumb TVs
Or you can just treat your smart TV like a dumb TV. If you ignore the smart part, they generally work just fine as a monitor and speakers and HDMI input switch with ARC and CEC. Choose your TV for the picture quality and whatever other features you want. The cost penalty for buying smarts you don't use is usually very small. You don't need to connect your TV to the Internet. If you need to install a firmware update, connect it to the network then disconnect it, but you may never even need a firmware update if you aren't using the smartness.