I like the idea of having greater screen real estate, but see the product as prohibitively expensive. If it cost as much as a regular smartphone, I would consider buying one for my next upgrade.
My point is that your point is pointless since it doesn't account for basic physics. Changing the shape of something does not inherently change the amount of space it occupies. The volume of the convex hull of the fully-folded phone will be the same as that of the unfolded phone.
Your perception may be that the phone is smaller when folded, but the reality is that it is not. I understand that you are resistant to this cognitive dissonance, which is why I'm trying to communicate it to you.