The license plate itself isn’t the issue. The state want cars to have an easily visible identifier? Sure, whatever makes sense from a perspective of being able to identify a car and its likely driver at the moment when it's actively being used for a crime or for traffic enforcement.

The problem is that this state mandated visible identifier is then used by them to constantly track where you go. So the question is do you have the right to not have the government tracking your movements and keeping logs of everywhere you’ve been for months or years, especially when you’re not currently suspected of any crime?

Depends a lot on whether the applied definitions of “expect” and “privacy” are meaningful, as well as on effects that were hidden for 100 years before new capabilities arose. Machine guns are mostly illegal.

With a straight face, I expect that it is too expensive for the police department to hire a human to stand at every highway on ramp and offramp, and to write down every license plate of every car that drives past them, and then furthermore for it to be infeasible for them to pay a human to search those records and replay every place I've been, for funsies. If I'm Al Capone, that level of effort is warranted, but to be able to do that for everybody and backdated too? Yeah, not OK.

Historically, it has not been possible to do that. That technology makes it possible for that to be possible should be balanced with the fact that it wasn't remotely practical.