Until Amazon is offering simulcasts they're not really competing.
[1]: https://www.amazon.com/dp/B06ZZNKX78/ [2]: https://www.animenewsnetwork.com/news/.105749
I'm very ignorant of Japanese or Korean dramas/live-action programs.
A simple modern example is being able to listen to the announcers of a sports match on radio or watch the same announcers via the television transmission.
Google defines a "simulcast" as a simultaneous transmission of the same program on radio and television, or on two or more channels.