I have 4 TV's. A 2014 Samsung, a 2016 LG, a 2018 LG and a 2020 LG. They all have 5 GHz.
It's probably harder to find 1 without 5GHz than it is to find 1 with it.
My most recent TV is my LG CX. I wouldn't even consider blocking internet access for the tv.
LG have added half a dozen features since I got the TV and fixed a number of bugs affecting my usage.
I use numerous apps on the tv which wouldn't be possible without internet access.
TV's send random anonymous usage statistics online but you can opt out of that on many TV's.
The TV will use next to no bandwidth unless streaming via an app or downloading an update.
Updates are usually once every couple months at most on a new tv from a well maintained tv brand.
Less or not at all on many other tv's.
If you really have security concerns about connecting your tv to the internet then can I recommend
this security device.
I also recommend turning the toaster around just in case it is watching you.
Just a joke obviously. I've never understood the paranoia regarding certain devices being online or not. Cameras I can understand.
I'm not bothered if some Korean TV company knows I watch Judge Judy or if some Chinese company knows I turned my smart light bulb on.