cryptocurrency: Has always made me nervous having money that is not in your hand and relays on the internet. Internet goes down so does your money. Relaying on the health or memory of another to safeguard your money.
When I was a BBS Sysop in the 1980s, we had a form of cryptocurrency, although I don't think it was called that at the time. Banks didn't like dealing with BBS's so setting up a shopping cart on a BBS was expensive and difficult to put together. There was a form of BBS currency - it might be the same one that is known as BBSCoin - that could be used for BBS registrations, to buy BBS software, and so on. A few companies would accept BBS currency for modems and, in some cases, even computers, but it wasn't thought to be reimbursable in actual money.
Cryptocurrency,like Bitcoin, is simply another fiat currency. In this case, it is kinda like having your savings in a thief-proof vault the key/combination to which has been lost.
I'm sure someone will end up hacking and getting those passwords...but we may never hear the truth about that either.