I'll give you an upvote for discussion purposes, but I think your example is oversimplified to the point of not really explaining true purpose of crypto or how revolutionary it is.
I understand the desire for simple explanations, but when something this novel comes into play it will take more. Think how hard it was to describe the internet to someone before it existed, that's what this is like. I would say your example is analogous to explaining what the internet was by just saying mail is now email, but leaving out the revolutionary technology that is the WWW.
This tech is mostly about taking back control of our money (which is really our time and labor). A small group of unelected private parties currently control our time and labor. This is an insidious form of covert slavery.
In short the analogy I would make is this is the Internet of money. For example- in in the past, news was a monopoly of a few small newspapers, and then the internet made it possible to have complete freedom of information for the most part.
Crypto is the same but for money. Until now small groups controlled the money of billions of people. Now we can have complete freedom over that too.
RE: Simplest Way to Explain the Value of Cryptocurrencies to People Who Just Don't Get It