Based on the docs, this project would appear to contain both a "low level" webauthn library and the "credential platform", i.e. the UI and service executable. however, it looks like it's not possible to build/use the webauthn library standalone.
The main point of this project is off course the service executable, offering "platform auth", but using it as a library might be a nice to have as well. For this, it would be great if the dbus and UI dependencies could be separated out. This could offer the ability to use the library to build cross-platform apps with the FIDO2 built in, without needing platform specific things like D-Bus, UI stuff and Bluez.
My current use-case is testing support for authenticator hardware in Windows. While D-Bus is available on Windows, building and running the full service executable on Windows is probably challenging and beyond the scope of what I'm trying to do.
My end goal is supporting something like xdg-credentials-portal in the Webauthn client library I'm working on.
To be clear, I think where possible platform auth should be used, but a low level library would facilitate testing.