> The windows registry (configuration manager is the real name btw) does a good job of abstracting configurations, but obviously you can't pick and choose the back-end implementation like you potentially could in Linux.

In theory, this is what dbus is doing, but through APIs rather than arbitrary path-key-value triplets. You can run your secret manager of choice and as long as it responds to the DBUS API calls correctly, the calling application doesn't know who's managing the secrets for you. Same goes for sound, display config, and the Bluetooth API, although some are "branded" so they're not quite interchangeable as they might change on a whim.

Gnome's dconf system looks a lot like the Windows registry and thanks to the capability to add documentation directly to keys, it's also a lot easier to actually use if you're trying to configure a system.