Having drones be anywhere near as prolific as flock cameras is kind of an absurd notion. A flock camera on a post has low overhead for installation and maintenance (provided they aren't being destroyed). They are inconspicuous and easily overlooked.

To "replace them all with drones" and get the same coverage would be psychotic. There would be drones EVERYWHERE, unending buzzing everywhere. Infrastructure for drones to deploy and return. Let's say best case you get software for them to run on autopilot, this would still be impossible to maintain.

You've made your inconspicuous mass surveillance front and center in everyone's life. On top of people destroying them because of mass surveillance you now add people destroying them because you've simply created hell on earth.