this done well is a transformational thing, its just no one has been willing to invest yetI think we've seen this before. Back before phones were "smart" there was one (Nokia, maybe?) that you could put on a little dock into which you could plug a keyboard and monitor.
Obviously, it didn't take off. Perhaps it was ahead of its time. Or, as you say, it wasn't done well at the time.
Phones accepting Bluetooth keyboard connections was very common back in my road warrior (digital nomad) days, but the screen was always the annoyance factor. Writing e-mails on my SonyEricsson on a boat on the South China Sea felt like "the future!"
Slightly related, I built most of my first startup with a Palm Pilot Ⅲ and an attached keyboard. Again, though, a larger screen would have been a game changer.