I could tell you about the new device, but then I'd have to kill the internet.

Anyway, hardware keyboards are good for text input, I guess we all know this already. Keyboards a) give haptics both before pressing keys (feeling where you are) and after pressing keys (the latter can be emulated, but the former is much harder), b) using a HW keyboard doesn't block half or the whole of the screen like an on-screen keyboard does, preservering the context better and simplifying the UI, c) error rates are usually smaller.

Then again, just like with other hardware keys, it's a question of positioning a device, as for something where people type a lot or then type a little. A keyboard adds cost, mechanical complexity, size and weight to a device. The UI should also work in a device without a hardware keyboard.