The only solution I use is connecting the TV (LG OLED) via ethernet and set a traffic rule to drop all outbound internet packets from the TV and then have an Apple TV for viewing.
However, I bought my Apple TV in 2022-2023 when it was like £129, so excellent value for money, not so sure nowadays.
The reason why I keep it connected to the network (with a traffic rule) is I use home assistant to run automations etc so need at least LAN connectivity.