People want a full-size keyboard. Adding a couple of millimetres underneath that keyboard allows you to put a whole computer in there.

We have laptops because it makes sense. Look at Apple's Macbook Neo. The tiny logic board on that computer is the least of Apple's worries. The most expensive components are the display and case. Why not charge 100 bucks more and not have to worry about this thing being a phone accessory?

Yeah, that's basically my point.

The only way it would make sense to use your phone is if the keyboard and monitor can fold up so small that they can attach to the phone and still fit in your pocket. Otherwise, just using a laptop is going to be better every time.