The platform security guide PDF (May 2022) on the page you linked is a lot more detailed and explains it better https://help.apple.com/pdf/security/en_US/apple-platform-sec...

The escrow is only an additional layer of security - your device still has to decrypt the downloaded keychain contents using your password AFTER proving to escrow that you're allowed to download the encrypted keychain using device or SMS 2FA or an iCloud security code.