The next time a western country has a civil war, you can expect that one or both sides will be using drones, at least for surveillance if not for offense.
While it's true that the things on AliExpress could be built by a dedicated hobbyist, a typical large city would only have 100 to 1,000 people even capable of putting together a computer vision module in a couple of months' time. Selling a computer vision module on AliExpress puts that capability in the hands of anyone that wants it at the speed of FedEx.