The only way to make profit on bitcoin is to make someone else poorer by that amount. That's what makes it a ponzi - anything with this property that pretends to be an investment is one. Implementation details are irrelevant.
>Goods and services provided by humans have no intrinsic value but become precious simply there being demand by other humans.
Nonsense that's easy to disprove: try to stop eating food and start 'valuing' dirt as food. You will, of course, starve to death. Why? Because actual value is objective and exists regardless of what people think.
Intrinsic value objectively exists, but in most cases can only be estimated, correctly or not. It depends both on location and time coordinates.
Civilizations that estimate objective value too incorrectly collapse or get conquered. Those that estimate it correctly enough prosper.
The long term metric for any civilization is fortunately clear enough - energy use, also called the Kardashev's scale. It's a long term metric because foolish civilizations can waste energy in the short term (eg. by mining bitcoin) - but because it's wasted it results in less available energy in the future.
In cases like bitcoin there are no unknowns - it objectively has negative value and destroys wealth. It's backed by nothing and generates no income.
Don't get me wrong - I'm not saying don't play in crypto.
Never in history was it so easy to get rich by extracting wealth from others - which is what bitcoin and 99% of crypto in general is for. Is it a scam to promote it? My personal definition is pretty simple: it's a scam when promotion involves lies. Telling people bitcoin has value, while being a developer (thus smart enough to know it's worthless)? Scammer. Telling people it may go up in price (because other people may buy it)? Not a lie.
China was smart to ban crypto - they're too big to hope to profit at the expense of the west, and in fact most coins and tokens are held by Westerners, virtually guaranteeing it would end up as wealth transfer from China.
Crypto tokens can have real value - if they monetize efficiency increase in the real world. A smart contract economy is a possibility and it can exist - but right now it's all in the proof of concept stage. Without the ponzi factor I think eth should be valued between $1B-$10B (based on future potential, not current income), other smart contract platforms collectively at 20% of it, some defi tokens like MKR in the upper 8 figures - lower 9 figures. Everything else - worthless.