It's a standard supported by multiple parties, not just Microsoft, including multiple open source password managers.
And it does provide some benefits: phishing protection (no shared secret that can be intercepted or given to the wrong party) and the service does not need to store as much sensitive information (don't need password hashes that could be leaked and cracked, just a public key).
And it does provide some benefits: phishing protection (no shared secret that can be intercepted or given to the wrong party) and the service does not need to store as much sensitive information (don't need password hashes that could be leaked and cracked, just a public key).