Its secondary value is buying and selling legal goods and services on the internet without having to deal with credit card companies, but only for techbros.
Nah. Far more people use crypto for speculation than for actually illicit purposes.
But outside of a couple of meme articles about how "someone bought a house with BTC!" the only use case I can find for crypto is money laundering or ransomeware.
"Lihe Pharmaceutical Technology Company, based in Wuhan, Hebei Province, China, was charged with fentanyl trafficking conspiracy and international money laundering, along with Chinese nationals Mingming Wang, 34, who is the alleged holder for three bitcoin accounts shared by sales agents for Lihe Pharmaceutical, and Xinqiang Lu, 40, the alleged recipient of funds via Western Union on the company’s behalf. " [1]
[1] https://www.justice.gov/opa/pr/justice-department-announces-...
Fiat money derives its value from what you say, indeed. It is traded on exchanges because of that. But fungibility is only one of several factors. Money should also serve as store of value, but how long is highly debatable and the point.