> DIY hobbyists may also find it more difficult or impossible to source parts for their projects.

I mean not really. A quadrocopter is a remarkably simple thing made out of extremely generic parts: 4 DC motors (and ESCs), a radio, a computer, a battery and an inertial measurement unit. Anybody with a rudimentary amount of electronics knowledge can build one, the components are extremely widely used. The most unique parts about them are the frame and propellers, which are pretty easy to fabricate.