Thanks for the tip, I might get one of those :)

It is possible to put it in a VLAN that is unable to talk to the internet. This is fine, but I wish I could just get a TV that doesn’t have this tracking functionality to begin with.

Please tell me where I can get a modern high-res TV that is NOT smart. I have tried but cannot find them anywhere

Which ones are you thinking of? Out of the options I am aware of, Signal seems to be the most secure, most reliable, and most privacy respecting messaging app in this category.