Because it makes more sense to have software do one thing good and not many things bad. There are many examples of this, iTunes is a classic but also Jellyfin, I like that they’re focussing on video because that is very complex in itself. To also do comics, podcasts, audiobooks, comics, books etc. meana much more complexity, things that can influence and trip each other, diversion of work etc. Yes, would be very cool to have one app that can play everything perfectly but that’s almost impossible. To do one thing good isn’t.