Taxes and AML/KYC kill this. People need to surveil their customers in order to comply with legal requirements. As soon as money is involved there's so much bureaucracy people just contract it out to intermediaries like Stripe and by then payments are anything but micro.
The real innovation of cryptocurrency is that it allows people to think outside the box of AML/KYC.
Stablecoins, which not decentralized at all (and thus defeat the entire purpose of cryptopcurrency) are allowed to break the rules by wearing the label of "cryptocurrency", with the implication being that cryptocurrencies are just going to break the rules anyways.