That can be achieved if you are app-centric as well (i.e. Spotify app in al lthe places), but your point still stand nonetheless.

Agreed, if you’re a single-app user then something like Spotify works just as well, as long as they do a great job of maintaining to-the-second sync across devices. Audible does a good of that as well.

That just puts you in the space of needing all apps to be available on all devices.