It’s interesting that the predominant “form” for the smart phone has been a single vertical screen. So the fold out phone like Samsung’s is still keeping that form, but the Surface Duo actually changes the “form” to two distinct screens.<p>A habit change that I think will be too hard for consumers to palate right now.
TL;DR = A tablet-shaped device without a front facing screen is appealing only to a limited audience with specific use cases in mind, notably not making calls or consuming audio/video content.