[justinschuh]

System credential managers are the established way to do this properly. They are user configurable, generally maintain credentials in a separate security context, derive a strong key from the user logon credential, can more easily support hardware security mechanisms, and introduce minimum user friction by default. That's why Chrome and most browsers prefer the system credential managers when available (on Linux: libsecret, Gnome Keyring, or KWallet).

The application specific "master password" is more of an anti-pattern for effective credential storage. The most glaring issue is that user friction is so high that it's rarely ever enabled, because it's just too inconvenient and confusing for most people. But beyond that it has the weaknesses typical to any credential manager not deeply integrated into the OS (e.g. credential management is handled entirely in the user's context, management is inconsistent between applications, etc.).

[mschuster91]

I don't get the advantage of system credential managers - at least as long as the user is logged on, I can always hook myself into a browser process and retrieve the passwords.

The only advantage system-level password storage has is when the attacker e.g. wants to get the passwords from a forensic image or such.