Airplay is still a player because it's easy to use... sure Apple have made it harder and harder over the years by 'streamlining their products'*, but people still understand the process. Punters 'get' Bluetooth, Airplay and GoogleCast - opening another app to stream something is in the too hard basket, even if it's super simple and intuitive... So it's here to stay for the immediate future from what I can tell.
I'd be annoyed if I was a Denon / Apple / B&O customer who has been waiting for the Airplay 2 rollout though, they were promising it last year!
*it's their way of making things more convoluted
This industry is not getting cheaper and cheaper, we're simply convincing ourselves that we have to push the cheapest option to customers. #makesonosgreatagain