>> A difference in degree (of usefulness and speed), not in kind.
No.
Automating the system is ABSOLUTELY a difference in kind.
The argument "it is the same thing" is reductionist beyond absurdity.
"Quantity has a quality all its own."
Scaling and automation is a difference in kind in every field, and especially in surveillance of a population. To deny it is to assert the Industrial Revolution, the Computer Revolution, and the Internet had no effect on anything.
A cop sitting by the road operating a speed trap time or radar/laser gun can trap enough speeders to moderate the traffic, and individual speeders get few tickets. Implementing the "same" thing with cameras everywhere and timing toll-booth arrival/departure times and issuing tickets automatically would result in the majority of drivers getting multiple speeding tickets every trip (just based on measured average speeds on most roads exceeding the posted limit).
Your example proves the opposite of what you say.
Having a cop personally observing and writing down license plates requires resources - a decision to prioritize those specific resources for that specific investigation on that day. It is a real decision to surveil people in that way. It means people will ONLY be surveilled in that way when it is important.
In contrast, constant, ubiquitous, and near-cost-free surveillance means people will be surveilled all day, every day.
What was once applied only to exceptionally serious crimes is now available to target any citizen for any petty crime. It enables exactly the kind of silent targeting for which every authoritarian government lusts — the appearance of law and order with the ability to target any specific "troublemaker" at will.
With such surveillance, there is no need for an authoritarian to make false charges or highlight a protest. Jack protests, they don't like it, just say "go after Jack". They go to the cameras, find a bunch of petty crimes, and prosecute. Jack now has endless trouble if not jail, and the regime carries on like nothing happened.
If, as you say, you don't understand why it is not different, stop being reductive, look at the larger system.