Most people use plastic these days. Credit companies charge upwards of 26% interest as well as transaction fees. Then there are the Payday loan sharks in every town and city. What they charge should be illegal. So, I don't know why anyone would get their panties in a wad over crypto exchange fees rates that are 0.5% or less in most cases. Yes, there a re kiosks that will rob you on transaction fees, but there are plenty of alternative. Coinbase for instance, one of the larges exchanges, doesn't charge any fees if you transaction with another member - and the it's instant.
Sumpin else, if everyone would suddenly switch to using checks, or cash, it would collapse the economy. Credit card companies create more than a trillion dollars in fiat out of "thin air" just by how they operate.
Wrong! The central bank would just adjust the amount of currency in circulation for what is needed. That's how it has always worked.
And as far fees, my response was to someone that was making a claim that poor people who could not afford a checking account could use digital currencies. In your example of 0.5% fees, $1000 in monthly bill payments would equal $5, about the same as for a basic, no frills checking, so NO REAL ADVANTAGE.
Bringing in payday loans is absurd.