I suppose I'm splitting hairs.

Yes, a proper email authentication stack has DMARC + SPF + DKIM. But each of these is a separate protocol.

This also doesn't take into consideration the other protocols that have arisen BIMI, APRF, MTA-STS / TLS-RPT and are at even lower levels of adoption.

MTA-STS is useful (but it's about helping receivers by demanding mail is sent encrypted, not senders with delivery).

BIMI is a pay-to-spam protocol that helps senders, you can add a rule to postfix to mark it as such.

APRF is a draft, and likewise helps senders, not receivers.. not sure why anyone would want to adopt this standard. A little closer to DMARC reports, but sharing PI that you owe no sending server.