If it's doing some kind of "always scan WiFi in the background" shenanigans then it's still a computer slowly going out of date without security updates and occasionally exposing itself to the local area.
I wish I could take a "smart" TV and flip a switch and have it gracefully fall back to "dumb" TV where the Android device is physically disabled.
Chromecast is basically a smart TV on a stick, controlled with a remote from smartphone (and partly, even the remote control of the TV). You can run a Chromecast wired as well. Same with Steam Link. It can run over wireless or wired.
I find on all of these wired far more reliable, and I keep more bandwidth for my wireless applications. Even my printer is wired. Then again, I got a 8 port gbit switch for connectivity and barely any wires visible.
The caveat is that my smart devices, although wired, are currently NOT on a VLAN, and that Chromecast is a data resource for Google, and as I mentioned the EPG data on the TV contains commercials. Instead of the Steam Link I could even just run a HDMI cable straight from computer. I can also plug in a Bluetooth USB adapter on my USB hub to listen via Bluetooth on the couch to the TV.
Other than that, its a great TV for its price. Make sure your TV has enough HDMI ports. You might also wanna have a look at Chromecast alternatives such as Miracast devices or Amazon Fire Stick (the ethernet adapter came free with Chromecast Ultra but for the other Chromecasts it costs 20 EUR extra).
Edit: mainly cause they'd stopped working years ago...
I realize it's a bad solution, but that might work…unless it's "smart" enough to realize it has no connection and try other networks regardless…