The idea of a stock is that it is worth the present value of all future dividends. Stocks that do not issue dividends and are expected never to issue dividends are indeed a Ponzi. I think those are by far the minority of stocks.
The idea that stocks that never issue dividends are somehow only valuable because other people think they are valuable (let alone calling it a Ponzi) is completely misguided. I mean if a company builds a pile of cash and never distributes it to shareholders it's still very valuable to have a say about how that pile of cash should be spent. If a company ammased a billion of cash there will be many takers to buy it for less than a billion just so they can direct that billion somewhere.
Of course there is also an option of closing shop and dividing the assets to shareholders or myriad other ways of making the assets valuable without paying dividends.
Those kinds of basic misconceptions about financial markets is what crypto evangelist prey on. It sounds pretty convincing to the ignorant but is just nonsense under scrutiny.
