Really not sure what to make of this: https://bitkey.build/screens-are-not-a-panacea/

The security model seems to be that the hardware device essentially acts as a confirmation button for all operations prepared on the server...?

That seems like a pretty big step down from trusted channel based solutions that can actually achieve "what you see is what you sign". I don't see why the proposed improvements couldn't be just that: Improvements to a secure input/output device, not replacements of one.