You're missing the forest for all the trees. Another popular ponzi/pyramid scheme, Amway, has "products" that get bought and sold. No one actually wants, or uses, or cares about the products- they are identical to the same stuff you can get at any grocery store or Walmart, and sales of them is not the main point of the scheme. The products exist to make the whole scheme look like a legitimate business, when the real meat of the scheme is in setting up pyramids by conning others into setting up more dealerships. Everyone of those dealerships has to pass money upwards toward the top of the pyramid. The emphasis is never on selling products- it is always on selling dealerships.
Bitcoin claims to be about making transactions across borders and currencies easier, cheaper, and faster, but that is the ruse to make it look legitimate. The real aim is to get people to buy bitcoins with real money (thinking it is an investment) so that people at the top (the ones with piles of bitcoins- i.e. the ones who came up with this scheme) can cash out in a big way.