DID was created so that we could all stop using passwords. Most of us have too many passwords and we don't like using them. Users not wanting to remember the details of another account is a reason for many failed sign ups particularly for smaller websites.

DID is an Identity Provider, that authenticates users by verifying access to either an email address or securely stored private key. We use whichever is easiest for the customer while matching or exceeding the security requirements of the site.

We want to take care of making great authentication so developers can get on with building the rest of their business.