App-only mode on android tv has a giant ad banner before the apps icons. It's much better than regular mode, but it's still a giant ad. It's been the case on all my Android TV devices. If you don't see it then I guess it must be disabled in some regions?

https://9to5google.com/wp-content/uploads/sites/4/2020/09/go...

But on the Apple TV you don't need to enable or disable anything. There are no ads, there has been no ads and I'm pretty sure there will be no ads.