No, that's not true. macOS has multiple keychain APIs with different capabilities.
https://developer.apple.com/documentation/technotes/tn3137-o...
Items within the traditional keychain can have ACLs applied to them. When you run `security dump -d`, it will only be able to dump items from a traditional keychain that are either set to allow access to all apps, or that have an ACL that grants access to `security`. Very few items should be set to "Allow All". In my login keychain, almost none are.
For all other items you will get a security prompt with "Always Allow", "Allow", and "Deny" which requires you to enter your password. You can also set items to require confirmation but not require the keychain's password.
If you add `security` to an item's ACL--say because you need access to that item from a script--then any app can of course access that item by calling `security`. My advice would be not to add `security` to any item's ACL.
AFAIK, `security` has no access to the iCloud Keychain where Safari stores its passwords. If you don't have iCloud Keychain enabled, I believe Safari stores its passwords in a traditional file-based keychain but those items should have ACLs on them.
https://support.apple.com/guide/security/keychain-data-prote...
https://support.apple.com/guide/security/icloud-keychain-sec...