It seems to me that comparing something that is intended to create a new category of device against current categories is flawed. My read of this take on the Microsoft Surface Duo is that it is designed for productivity, smartphones are not designed for productivity, but we will compare it to smartphones anyway.

In my opinion, the real problem with the Surface Duo is its price. Anything that requires one to spend >$1,000 demands more discretion. Right now the price is a barrier to entry that is going to prevent Microsoft from selling many units.