Why would you save personal data on a centralized server when you could store that personal data on a locally? This has to do with the security issue of keeping all your data on a central server. A centralized server with thousands of people using the server creates a bigger target for hackers than just storing your personal data on your own devices.
With this approach, you can implement secure storage of sensitive password data with a simple touch of your finger. Thanks to fingerprint biometrics technology! I'm sure you already use it to unlock your phone, why not protect your passwords and any other data you choose locally.