Where is the end product? Why isn't it available?
Because it costs several billion dollars to create the whole infrastructure needed to make any of these things at an industrial scale, while the infrastructure for Li-Ion one is already in place and can be cheaply adapted to new improvements on the already proven technology. Besides, Li-Ion has the "advantage" of forced obsolescence, requiring user to purchase new ones for their devices every few years.
Down the line it might be worth it to invest in these new technologies, particularly if some new technology appears that requires such massive power densities and speeds and there's huge demand for it, as was the case with electric cars and the new battery tech they require. Right now however the economics of scale, coupled with the potential lower long term profits, don't favor investing in it.