I agree with most of your assertions.  Let's explore the "4 tests" w/ cryptos:  Durable?  arguably yes.  The block chain journal ledger lasts forever in cyberspace.  (even crooked Hillary couldn't erase her 33,000 emails).  Fungible? That's how some tech savvy Venezuelans are feeding themselves now.  Divisible? Yes. Purchases with bitcoin to vendors are easy.  Portable?  On my cell phone.  A gold/silver backed crypto with trusted, secure journal ledger block chain would go a long ways to eliminating money laundering corruption in the current system. We'll see!  WWG1WGA!