You are correct. The attraction of a properly fabricated survival belt would be its increased utility. One almost always wears a belt, so lets expand its capability. Make it load bearing, like a riggers belt and devise some means of affixing various survival goodies. Then you could carry an altoids box and wear the belt, both with carefully and thoughtfully integrated components.

The cobra buckle seems promising. On all the rigging belts with which I am familiar, the steel buckles are rather heavy and not really suitable for routine wear. The fun is to customize this kind of gadget, thus avoiding blisters and such.

Back to the drawing board.