The claim that we are disagreeing with is that Bitcoin is meaningfully different from any other investment in a way that makes it a Ponzi Scheme. I'm not trying to persuade anyone that it's a good investment, just that it isn't a ponzi scheme any more than gold, oil, real estate etc is.
I don’t think bitcoin is a deliberate Ponzi scheme, but it does have Ponzi scheme-like elements, in particular the absolute dependence on a greater fool to take it off your hands, with value _purely_ being based on what other people imagine it to be worth (ie not backed by any intrinsic value). Gold, yeah, isn’t a million miles away from this, either (as I mentioned previously, historically it is a _bad_ investment) though it does have the benefit of a few millennia of cultural cachet, increasing the chances that there’ll be a greater fool along soon.
Oil and real estate are totally different, though investment in oil in particular _is_ rather speculative; you’re betting on future real demand, but that demand is at least, like, _real_; there are obligate buyers of oil, almost no matter how high the price goes. Real estate, as I previously mentioned, produces value in terms of either rent or not having to pay rent.
