From everything I've seen (which was a lot for a couple years due to my job) there were two types of burglars:

One type didn't care about any security system, even alarms. They would smash and grab as fast as they could and get out. They didn't have a plan other than to grab the first things that looked valuable. It might cost more to fix the building than to replace what they found.

The other type was trying to play it smart. As soon as they noticed the cameras or indications of a security system they'd leave. Lots of videos where a person was detected, looks up at the cameras, and then slips away to go find another house.

A lot of people start turning off alerts or never set them up properly, so they don't notice the second type of video unless they go looking.

[dead]