[AdrianEGraphene]

AFAIK, there are no permissionless payment rail that do fiat-> crypto payment processing. They all require intermediaries and presumably would run into similar issues.

Crypto-> crypto would be a different story, but requires a more sophisticated buyer.

I play in this space, so would definitely like to hear what you've got in mind.

[whatisweb3]

Imagining either crypto to crypto, or a permissioned rollup handling crypto to fiat that lets the sequencer block a users address for KYC purposes, but user can still trustlessly withdraw funds to mainnet.