You could use crypto for micro-transactions (it's one of the main problems that crypto was meant to solve). LiteCoin, for example, apparently has quite low fees[0] ($0.03-0.04) Monero much less than that. But enabling this in a frictionless manner for users is probably difficult (I don't own crypto myself).

[0] https://coinwire.com/cheapest-crypto-to-transfer/