I don't understand the "need" for things like those. What's wrong with a 99 cent gallon plastic jug of water, or a canteen?
Ever try storing one of those in a lift raft for five years?
They were originally designed for military and commercial survival kits (aviation and marine kits) that must be stand alone and survive environmental extremes with a reasonable shelf life. They are overkill for most peoples' needs, but they do have their place.