Would they really go as far as completely faking it? I don't know.
Of course not.
I don't know why these conspiracy theories keep doing the rounds, you don't need them to explain what's happening here.
It's not rocket science to make something like this, it's just a DC-DC converter on the end of a battery, it's just a minimisation problem.
They clearly have a real functioning prototype that admittedly seems to have some connection reliability/fit issues which would be expected.
This is simply a case of a novel idea by serial entrepreneurs/inventors that were hoping would make them a fortune, so they go blindly into development only to find that the practical reality is that it's only mildly useful. They likely had the best of intentions.
But they have to persist, because that's what these serial entrepreneurs/inventors do, especially when they have taken investors money.
They did not expect a big backlash from the technical community, they thought they could just flip a half-arsed product to Walmart etc and no one would care.
They don't release technical performance data because they know very well it will prove that the thing can't perform as claimed.