I don’t think I’d want to have them without the second device. Without a second device (with a screen), you’d be stuck with a voice interface for anything more

I don’t think I’d want to have them without the second device. Without a second device (with a screen), you’d be stuck with a voice interface for anything more complicated than play/pause, next track, and volume. And to put the CPU required for that, with storage would make the headphones too big and take too much battery.