I know its normal to get asked for license, registration, and proof of insurance. But why ask for the registration? When I register every year, the county sends me a sticker with the plate number and expiration date to stick on the lic plate. The cops van see the plate and date right? Plus I’m sure they run the plate when they pull you over anyway. Seems to me they already know the registration status.
So why do they still ask for the registration paper?


They don’t? The state removed the requirements to have your rego sticker on the left side of the windscreen because the police access to the registration database maintained by the department of main roads.
Which state? It’s different everywhere. Most still require you to put registration stickers (AKA tags) on your license plate.
I believe they were answering from the perspective of an Australian. The rest of the world gets the shits with the internet assuming an American perspective by default.
The one I live in, much like how op is talking about where they are.
In what countries?
OP never mentioned where they were from.