> all the old folks whose retirements are in indexed 401(k)s end up holding the bag as those investments become worthless and a younger generation ends up inventing a whole new financial system
If the world's investments cease to be made in actual companies, in favor of a meaningless commodity, we'll have much bigger problems.
All currency is a meaningless commodity. What matters is how it modulates the flow of real goods and services. A wad of cash is meaningless except as a claim to a share of someone's future productivity, after all.
It creates value for other Bitcoin investors, some of whom might cash out or directly spend crypto building a business. In principle, Joe's Can Factory could be funded by 100 bitcoin which Joe acquired years ago, and the social fads which drove up the price directly enable that.
Of course, right now, the only thing practical to fund with cryptocurrency is a cryptocurrency or internet business, none of which provide truly useful or necessary services
If the world's investments cease to be made in actual companies, in favor of a meaningless commodity, we'll have much bigger problems.