Cash has its niche. Bicoin creates a new one that has its advantages. Likewise both have disadvantages. A big disadvantage for Bitcoin is it’s the new kid on the block. Anybody remember when we didn’t have credit cards?
I can see how a thumb drive can be cash-like, if the grid is up. I’m not pooh-poohing the whole thing; just saying that physical cash has some attractions that bitcoin doesn’t seem to fill yet.
I do not remember when we didn't have credit cards but I got my first one only 51 years ago.