> Google will will link your new "anonymous" account to your established tracking profile as soon as you access it from a device or geographical location associated with your existing account. This is true even if you never visit any Google owned domain, through the magic of shared tracking IDs.

A separate device is <$50. Local VMs are ~free. VPNs hide "geographical location" and anyway they were never unambiguous because there can be arbitrarily many people in the same place.

> Second, your position rests on the assumption that this hypothetical federal ID will be mandatory. How will it be "required"?

If you make it easy to use and use of it allows you to be tracked more effectively then websites that want to track you more effectively will require its use.

> but they can also just require your identity today.

That is more difficult to do now and so they do it less. Making it easier would allow them to do it more, which is bad.

I mean there are two options. One is nobody would use it, and then it shouldn't exist. The other is that people would use it, which is bad, and so it shouldn't exist.