Then it sounds like your argument should just be "this is too risky for more than a tiny investment unless you're very secure," which I agree with.

Where I part ways is in your claim that the price is somehow illusory and it's impossible to cash out. Until recently I worked for a company that was mostly paid in crypto, and had no trouble selling it off, moving the money into a bank, and meeting payroll.

Crypto is new and the market infrastructure is immature; that means there's more risk, and also more return, just like the early days of other new asset classes that have arisen over the past century. William Bernstein wrote about this in his recent Investing for Adults series.