These remind me of the Spengle carbon monocoque MTB wheels. Those were a thing in the 90s, but they never really caught on.
The company and its wheels have been revived recently, however.
Yeah, I don't really see the point of these.
For gravel, IMO the rim dimensions are almost too narrow and dated.
They might be more durable. But then again, I think a properly built and tensioned spoked wheelset will be just as bulletproof and lighter at the same time.
The only thing I can see is that there might be an aero gain, depending on the spoke's cross section. But is that really something you're looking for in a gravel bike? Particularly of you're running huge tires anyway?
And, wheels like these will probably be incredibly stiff under pedal load.