Well, the US could follow Europe here if it wanted - in 2015 we've been capping CC fees at 0.3% and debit card fees at 0.2% and at the same time capped per-transaction fees at 5 cents [1], and whoops, suddenly the acceptance of cards in Germany exploded. I can pay the 50ct fee for loos on train stations or 1€ for a soda on a vending machine with cards.
The solution to micropayments are not shitcoins, the solution is to squeeze the rent seekers.
[1] https://www.consilium.europa.eu/en/press/press-releases/2015...