I teach with my computer and my video connection is the current Apple TV 4K. I have no problem using airplay to reach the AppleTV. Here are my issues…
I loose my ability to use wifi as soon as I go into airplay so I cannot show the students things on the web.
I cannot play a DVD using airplay.
I cannot use my itune/appletv account to play videos over airplay. I do not want to log the Apple TV itself into my account because it is the schools apple TV.
As near as I can tell Apple has killed these features to boost their own objectives.
This is sending back to the world of needing an HDMI wired connection to the AppleTV located in the ceiling…thank you Apple.