The existence of a license plate indicates that motor vehicle travel is not intended to be untrackable. That makes sense since these are powerful devices. It seems like a fair trade off since a motor vehicle provides many benefits but also high risk.

In a vacuum, I agree. But, license plate readers aren't limited to investigating crime/misuse of vehicle, nor are they limited to the government.

Tracking vehicles and linking that movement to individual movement (and spending and browsing and and and) used to be massively expensive, if not impossible.

Now all that tracking is "cheap" and being done at scale for all sorts of reasons.

Why stop at tracking license plates? Once you've started you should report on pedestrians, bikes, whether people are at-home, which building people are entering, the way they walk and many more. Those are all "alternative revenue streams" that are as valid from the operator/investor point of view and completely unrelated to whether the way of transportation or activity is meant to be untrackable or unrelated to a way of transportation at all.

There is also a factor of scale: a cop can follow you, but a system where everyone is monitored 24/7 is a very different story.

The existence of IDs indicates that people are not intended to be untrackable, whether on or offline.

This is a fair trade off, because…

By your logic, there can be no argument against universal web tracking, let alone universal purchase tracking, etc.

What does being a powerful device mean in regards to location tracking? Safe operation tracking makes sense, but location doesn't.