Im not really sure a digital wallet that can be shut down on a whim by some petty tyrant or permanently smashed by an EMP is the answer either.

I do think eventually a gold/silver backed blockchain currency will be used but it must have also have a physical manifestation.

Todays commerce is way to vulnerable to interruption through natural or other means. Shit if the power goes out stores have to shut down because they have no way to complete a sale without thier machines. They have no way to even accept money. Thier readers dont work, their registers dont work.

Im not really sure a digital wallet that can be shut down on a whim by some petty tyrant is the answer either.