I think none. There is a bank involvement that's why (fiat).

Before it's possible via LocalBitcoin but they have a mandatory KYC now.

Paxful allows Paypal but it needed KYC as well. Read the terms here about verified and unverified users: https://paxful.com/support/en-us/articles/360021175133-Is-ID-verification-mandatory-

This is only based on my own idea. You can wait for other responses.
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Totally agree, I believe that P2P is the only solution (as far as I know), but it's extremely hard to find someone who can trust new buyers with no reputation  (a trust issue).