I don’t know why it happened in your neighbourhood but when I lived in Monschau, I had a Freiganger and there were at least five other cats outdoor all the time. We had plenty of birds. But we took care of our gardens so there were so many insects. Bees, wasps, hornets, flies, mosquitoes of various kinds, ants, spiders, occasional hummingbird, everything. Not many rats. Some mice. Those cats kill a ton of mice.

Now I live in the city. No cats but rats and people walking dogs dumping on the sidewalk.

I take a suburb with cats.

Edit: of course, I don’t deny that cats kill a staggering number of birds.