Jeremiah, TIL Apple already shipped a functional equivalent in Safari of the terrible Chrome Web Environment Integrity API proposal.
https://httptoolkit.com/blog/apple-private-access-tokens-attestation/
It is less of a threat because Safari does not have Chromium’s market dominance, but it’s still bad and we should be demanding Apple remove it too. @webkit
I am grateful for Firefox recognizing the threat this proposal is to the open Web and opposing it, but the opposition won’t matter unless people use a different browser.