An Amazon driver left a parcel for me and didn't ring the bell, then a few minutes later someone stole it. I ran outside, chased them down and took it back.
The police took the report, but obviously they weren't interested in coming out to take the details of the thief or help me recover the package.
The doorbells also notify you of packages that have been left outside and let you answer the door remotely, which are both useful even if you can't go Blade Runner.
A thief like that doesn't steal just one package. Multiple thefts like that can easily add up to a felony amount. This is why the theft still should be reported. The cops won't look for that package specifically, but they could bust that thief for something else.
Our package got nabbed, a person noticed the empty box tossed on a nearby street and called the cops. Cops got video from a near by house an image of a unique car; month later they saw the car, arrested him.
He paid for the package and got community service.
I'm cynical, but I imagine it goes like this:
"Hello, this is 911, how can we help you?"
"I'd like to report a 39.99 board game stolen off my porch, license plate ZXX-1234"
"Sir, this line is for emergencies. Have you filed a claim with Amazon?"
Porch cameras drive mass paranoia. If you're not prepared to act on the information yourself, you're just feeding your own fear.