Earlier quoted context omitted.
Not any more. I can access keychain passwords in Chrome on iOS.
It's Safari-only on macOS, as far as I know. It does work with iOS apps and it doesn't work on Windows. It can't replace a password manager unless you use Safari on macOS as your primary browser.
WFIW I’m using a plain text file in an encrypted disk image, because I started before I found out about Keychain Access.app, and I never actually trusted third party apps for security reasons and possibly paranoia, so I can’t compare UX quality, but it is available in a form on the desktop.