This document might help clarify the nature of MS Edge's password manager. I'm currently seeking a way to use it similarly to dedicated vaults in order to avoid adding layers to our security stack.
From what I've read (and been told by our IT technician), there's virtually no difference in terms of security and encryption. Only managed access seems to differ. Dedicated vaults feature more navigable tools for delegating permissions. Unfortunately, this adds yet another key to the chain, an app to everyone's devices, and a step to everyone's authentication flow. Browser extensions and mobile app integrations mitigate this, but it's not quite frictionless (I used Bitwarden for over a year before switching back to the browser's password manager).