A simpler explanation is that US doesn't have the banking infrastructure to support these kinds of micropayments. ACH transfers take 3-5 days and require you to

A simpler explanation is that US doesn't have the banking infrastructure to support these kinds of micropayments. ACH transfers take 3-5 days and require you to link a checking account. Debit & credit card transactions have high fees. Chargebacks/fraud are a constant problem. So no payment processor wants to take on this complexity and liability.