I empathize with these concerns but think they're outdated by a decade or two. We already have universal tracking IDs, we just don't see them because they're opaque and proprietary. We already use government identification online, we just do it in the dumbest way possible: "please upload a photo of your driver's license." We've got the worst parts of centralized identity and none of the benefits.
> They don't have some special magic that allows you to prove who you are in a unique way.
Yes they do, the magic is called "losing money." FaceGoogAzonRosoft have done everything related to auth that's profitable, but the one thing they will never do is build an office in your hometown and staff it with a person who can do deal with you as an individual and physically hold your two recent utility bills when corner cases or fraud or whatever require it. The government has already built that office and hired that person, and you've already paid for it, so you might as well get some value out of it.