LAPD helicopter tracker with real-time operating costs

I find it interesting that the question is "why don't they use drones". My question is: why so much air surveillance? I live in Germany. The only times I hear a helicopter is if someone is being rescued or if someones missing. I rarely see them at all.

Where in Germany though? Helicopters tend to be more popular to use for various purposes in very densely populated places, like Hong Kong or New York City, but you don't really see them much in rural areas except for emergencies.