Apple already shipped attestation on the web, and we barely noticed

It looks like this can be disabled (on iOS)[1]:

- Go to Settings

- Select your user account at the top

- Go to 'Password & Security'

- Scroll down to Advanced and disable 'Automatic Verification'

1. https://blog.cloudflare.com/how-to-enable-private-access-tok...

You can turn it off in macOS 13 as well.

https://support.apple.com/en-us/HT213449

System Settings->iCloud Settings (your name)->Password & Security->Automatic Verification.

I guess that's only for Safari, but not Chrome if you have that installed as well? Also, what if you never signed into your iCloud account? Is it impossible to disable?

It's specifically a Safari technology. Chrome does not implement this.

> Also, what if you never signed into your iCloud account? Is it impossible to disable?

If you're not signed in, then it's not enabled, because the iCloud account is essential to the process: "An Apple server validates your device and Apple ID."

And can't without Apple's blessing as it isn't a "verified" browser.

The ability to disable this is entirely irrelevant. If Chrome ships WEI the various Chromium forks will also let you disable it, even if Chrome doesn't. Or you can use Firefox.

The problem is when your bank, tax office or favorite streaming service starts requiring this to let you use their services. The problem is the ability for large fraction of casual users to have this at all.