A currency is a way of "liquifying productivity" -- what we have with crypto is a few people turning up early, claiming a stake, and waiting ~10yr until they can exit with a fleet of tesla, houses, etc. because theyve convinced people to accept their tokens as cash.
That's about as anti-productivity as you can possibly imagine. It's a transfer of production (eg., cars) to the unproductive. Holding bitcoin in order to spend it is asking the productive economy to subsidise you.
(1) It is a scam; and (2) as a currency, it's madness.
Are you calling a revolutionary technology merely a currency?
While the early bird cashing out a ~1500% profit of Amazon stock that they bought 10 years ago also depends on someone else buying-in, there is something intrinsically different between what an Amazon share in 2012 and an Amazon share in 2022 actually mean. The same is the case if they had bought IBM stock instead, and were now cashing out at a loss of ~35%. Their values now reflect the businesses as they stand today, as well as future expectations of what Amazon, IBM, and their respective markets will be like in the future.
The decision whether to invest or divest in each of them today can be argued with hypothetical if-then thoughts. If you are more convinced than the average shareholder that Amazon will be hurt by the epidemic of fake products and reviews, unionisation of its warehouse workers, and stiffer cloud competition, then you will think it is overvalued and may sell. If you believe IBM's research in quantum computing will be a game-changer, then you may believe it is undervalued and buy. And so on.
Compare that to the difference between 1 BTC in 2012 and 1 BTC in 2022. Other than the impressive increase in how much somebody is willing to pay for them, what has changed between 1 BTC in 2012 and 1 BTC in 2022? What if-then arguments regarding the future might be reasoned to believe that the value will increase or decrease, other than "someone will be willing to buy it from me at a greater/smaller price than I paid"?
How does that differ from the more obviously valid versions of rewarding early birds?