There is no Freeview.... Everyone in the UK uses Freeview and Sky and Virgin have their own versions. People are just used to plugging in an aerial and watching TV with the whole app stuff on the back end.
(For non-UK viewers: Freeview is the UK over-the-air Digital TV platform. It's an umbrella brand/standard for a bunch of channels for half a dozen different providers including the BBC, C4, ITV and various other commercial operators. It's what you get if you plug your TV into an aerial...)
People who just want to watch Freeview channels have a new-fangled device called a
Television for that. Apparently, though, some portion of of the UK TV-watching population must have worked out how to go beyond punching in a channel number in order to run Netflix, Prime, Disney, ATV+, iPlayer etc.
Apple's bigger problem is that any TV bought in recent years will also have those Apps built into the TV - and probably Netflix/Prime/Dismal+ buttons on their remote controls where you once might have found "HDMI 1/2/3" buttons. I guess you have to cross the TV maker's palm with silver for that (I'm sure Apple could afford it). Also, the iPlayer app on ATV is lame (no 4k or subtitles last time I looked) but since other providers have managed to implement such things I think that one is down to the BBC.
So many times I tried to get people and family members into these boxes, it never works because they have to switch source, no one can ever seem to work it out.
I'm assuming the people in question are "sound in body and mind" - making digital services accessible to people with genuine issues is an important topic that I wouldn't dismiss but I don't think that's the question here.
Given that, if they really want to watch something on streaming or play their Apple Music library (while you're not there to do it for them), they'll work it out. If they're not interested, they'll find another "problem".
True, the UI design on TVs is universally awful (and the UI design of most streaming apps is frankly sociopathic). Powering up the Apple TV first will do it on most modern rigs, though...
Apple TV needs to have a built in decoder for Freeview or it'll never be big in the UK.
Do you mean having a hardware DVB2 (?) TV tuner (a UK/Europe standard not used in the US) and a co-ax aerial connection to the Apple TV? Not gonna happen on what is primarily a streaming box, but if it did...
How does a channel-based service like Freeview integrate into the app-based Apple TV UI, though? You'd either need several dozen channel apps, or a "Freeview" app with it's own channel-based UI. Perfectly feasible but it's not going to help anybody who won't accept a "learning curve". If they only ever use whatever app lets them watch Freeview and punch in channel numbers, they don't need an Apple TV.
In any case, most - if not all - of Freeview is available via streaming, and while that means half-a-dozen different Apps on an Apple TV, Freeview
do offer a one-stop-shop streaming App for Android and iOS - just not on ATV, which is probably down to Freeview, not Apple.