[nicholasjarnold]

Maybe you use it as part of a multi-layered approach to personal digital privacy.

Without having hired a lawyer to dissect the TOS and Privacy Policy for Mozilla's new service here, I'm going to assume for the sake of argument that they will not sell the data to brokers. If that is true, then it's one more way to try and keep your true PII out of circulation. For instance, maybe you pair this with a high quality VPN offering, browser plugins or whole-network based stuff like pi-hole/etc along with also using aliased credit card numbers through services like Privacy.com or other similar offerings. Then when you "sign up for an account" or "make online purchase" you could use name like John Smith, private/aliased email, etc etc... This just puts distance between your activity and your true identity.

With all that setup you have at least _some_ chance of evading a decent amount of the persistent and invasive tracking that is beginning to be top of mind for many people.

[madamelic]

Service-unique email / username + service-unique credit card is good enough for, I'd estimate, 95% of people.

You are trying to avoid wholesale scoops of info and automated credential stuffing. If your threat model is people specifically seeking out and targeting you: godspeed.