Watch Your Security Cameras
If you have security cameras with an Apple TV app, like Arlo, you can use the app to live stream your security cameras to the Apple TV.
I used this to keep an eye outside my house when I was in the basement for a tornado warning. The Apple TV in my game room let me watch the approaching storm in 4K on my big TV while safely in the basement. The best of safety and storm watching.
There are new HomeKit Video options for some cameras as well that work with this type of setup and tie into the other smart home features. Look for your camera's app in the App Store on your Apple TV to see if this works.