Use Siri to Play On Your Apple TV + AirPlay Upgrades
With Siri on your iPhone or iPad you can now control your Apple TV. This isn't total control, but you can start the process easily enough.
Simply start Siri, or say "Hey Siri", and then "Play movie title on my TV".
We expect that you will need to be specific if you have multiple Apple TVs in your house, but this is a handy way to start a program even if you are in the kitchen and your Apple TV remote is across the room. You can ask Siri to play any video, show, movie, sports event or channel that you have access to, and it should start streaming on your Apple TV.
You also get AirPlay upgrades with iOS 12.2 that make it easier to use.