Unless they then do the most minimal amount of research and realize that unlike any other store of wealth, they can redundantly back it up in multiple locations.

You can even split up your key in an M of N format so that a) no single compromised location causes loss, and b) some number of storage locations can be lost without losing your key.

Can you do that with gold? Land? Art? Cash? Bonds? Stocks? All of these rely on either securing a single location where the wealth is stored and moving to another place is either expensive, risky, or necessarily impossible (land/buildings), and/or they rely on trusting some custodian to preserve your claim on that wealth.