We really don't.
The most important thing about authentication over the internet is that it enable people to create multiple separate accounts that aren't tied to each other in any way. You can get more than one email address or even phone number. You only get one social security number. If you're required to use that on the internet, it becomes a universal tracking ID. That must never be allowed to happen.
Meanwhile the US government lacks the competence to do this. All of their existing identification methods are either fully insecure (e.g. social security cards) or no better than anything corporations use (e.g. ID cards that can be lost or stolen or hacked). They don't have some special magic that allows you to prove who you are in a unique way. And trying to centralize everything into a single ID only makes it that much worse if you lose access to it or someone else gains access to it.
The actual solution to identification is redundancy and decentralization. You have e.g. a password, an app and an email for any given service. If you lose one you sign in with another and update the one you lost. If all of that fails, you lose access only to the service where it failed, instead of losing your whole life at once.
Never centralize identity.