Maybe just do not connect it to a network ever. At least I don't. I've used TV as a monitor for a while but after some time strain in the neck showed up I downsized to 32" 4K monitor
I'll choose to use the TV's app every time.
I have a higher-end LG 4K OLED with WebOS which is extremely responsive compared to others I've had, also it's rooted to block any ad-crap, but also you can do most of that at the DNS/Network/Router level if you have an issue.
Then there's the fact that the non-tech family members don't want to use more than one remote or fiddle with channels etc, my wife can press the Netflix button in the remote from TV off and have instant Netflix and tue surround sound on too.
Younger me would have agreed with you, but as a parent and husband, in my mid 30s, I just want an easy life.
This is slowly but surely not becoming an option. Beyond automatically connecting to any open networks, some models already will stop working until you give them a network connection to perform a 'necessary' periodic update.
Automatically connecting to open networks sounds like a potential legal quagmire, since aiui I’m not legally allowed to just use my neighbor’s wifi without permission.