How many years do I have to spend studying what, to be able to verify that ecash is 100% private as some developers claim online? Given that I am a lifelong professional fighter and poet?
For now, sure, fiat cash is still better than metals. But with time it may be getting extinct. Also, even now, dependent on amounts and jurisdiction, in some places it is easier to legalize undeclared metals than undeclared fiat cash. Legalizing will not be a thing in the future, but now still might be needed in some cases.
To verify metals from fakes is relatively easy now. Just buy a device or have friends working at major traders.