People don't decide which platform to purchase a movie from based on how compelling the streaming technology is. It needs to be a platform that's accessible on their device firstly.
https://help.moviesanywhere.com/hc/en-us/articles/1150052819...
https://www.cnet.com/g00/news/apple-itunes-airplay-2-coming-...
Apple Music's recently released web portal uses Widevine to do DRM (same as Netflix and Spotify web) https://tools.applemusic.com/en-us
FairPlay on Android surely has some bugs if this is the case ...
They did, they commented that iTunes had better streaming than Vudu:
"The system is way more stable at higher quality than competitors like vudu..."
Most people are not apple fanatics. Most people do not need to purchase the movie and value "portability" of such digital format. Most movies are not worthy of repeat views, esp at different locations. Most people do not differentiate that much between HD and 4K when watching at home, on a setup that is not a home theatre.
I also think apple has one of the most compelling digital movie purchase systems so it’ll be interesting to see if this follows the iTunes music biz model where they expand to more platforms and take over a lot of the revenue. The system is way more stable at higher quality than competitors like vudu, and they’re trying to do the right thing by avoiding this push to charge more than $20 per movie. Also backdating purchases to upgrade 1080p movies to 4K was a very slick move.