It shows that without websites prescribing how to achieve their communication ends, the exact same Web can be presented over practically any medium. Mediums, like audio, that many find cool and many others (e.g. the blind) find vital.
By being willing to break Web-compatibility, Rhapsode is able to take it's privacy protections to new heights. No trackers can run on it by design.
Here's some self-hostable webservices that should work well as "skills" for Rhapsode:
What matters is what Rhapsode sounds like, not what it looks like. Take a listen below!
Just write progressively-enhanced semantic HTML5, and you'll be fine.