There's a practical reason for the off-kilter design. "Foldable" displays, for all their engineering, still behave quite similarly to paper. If you fold a sheet of paper over on itself, you're left with a loop that you have to push down on to form a crease.
The problem is, Samsung can't have its display crease. There's the obvious aesthetic downside: It wouldn't be great to have a crease down the middle of that gorgeous 7.3-inch display when opened. But the more important challenge facing Samsung is that mechanically, at least from every demonstration of the tech I've seen, a crease would destroy the display. Right now these displays are still more "bendable" than "foldable."
All that said, I'm very impressed by the Fold's hinge -- it looks durable, attractive and is certainly the best solution to this problem that we've seen. But despite its good work, Samsung hasn't been able to engineer around the basic shortfalls of the display tech.
If you want a phone that opens similarly to the Fold, but without that gap, there are a couple of solutions. Samsung's designers could implement a deeper hinge that can house the bend without creasing it; until I saw the gap, that's what I thought they had done. Or, they could wait for displays to advance to the point where they can get something very close to a flat fold. In reality, future devices will probably utilize a mix of both of those to produce the device Samsung, with some expertly curated demos, basically pretended it had built yesterday.
As is, what we have is a device whose main selling point is also its main limitation. A smartphone that's as expensive as a laptop -- or buying high-end phone and a tablet. Hopefully, the Galaxy Fold will spark creativity in hardware designers and lead to someone perfecting this idea in the future. But at this early stage, I'm not buying it.