I'd imagine some standard similar to the encrypted hardware chip Apple uses might be a good building block to create an SSO system not tied to any particular service. It would generate a unique hash for each person that could be tied to accounts across the internet. The data would need to be sharable across devices and sync to let sites know you signed onto their system using your phone but now want access using a tablet.

All I know is I have 600+ accounts saved in 1Password and many share the same password because they are old and did I mention there were 600+? Since password managers don't function well enough to rely on them fully, it's a pain to have to generate unique passwords for each service and look them up when the site or app won't properly access your password manager.