> They really don’t, because vehicles are frequently driven by people who did not register them.
Someone else driving your car doesn’t prevent the police from compelling you to tell them who drove your car. The point is the police can come to you. Different story if the car’s stolen, of course, but license plates in fact are used often as the first point of contact to identify drivers, regardless of whether it is their car. Without the plate, there might be nothing to go on, right?
Your other corrections are valid, I was imprecise with my point. Do you agree with parent that plates are pointless? I was only trying to point out the utility and reasons for the existing system of licensing and registration, plates, IDs, and stickers. I can see parent is making more of a political statement than one of actual utility, but maybe also important to keep in mind that purpose and utility of the various parts of this scheme look different depending on who you are.