The interface can be definitely improved, but that requires actual research and resources to pull it off. But as of now, it's not that complicated and very well documented.
I understand that, it’s a lot of work and resources are needed. The most important aspect in this regard is features over UX. But for a casual user, not finding UI elements we’re used to makes it harder to want to learn it for a few use cases. So maybe I’m not the target (power user in ebook domain).
But dismissing any UI change as useless … maybe it’s far fetched.