Good luck getting an explosive payload to where I live.

I change that slightly to "Good luck getting an explosive payload."

The difficulty for an attacker is the explosive payload, not the delivery mechanism. If it were easy for an attacker to get an explosive payload there would be car bombs going off every day as an easier delivery mechanism than use of quadcopters.

Thankfully it seems to be relatively easy to prevent people from making explosives, at least outside of warzones in countries with strict border control, because random people don't have a valid reason to buy industrial chemicals or equipment, and especially not chemicals identified as precursors for making explosive compounds. And for plants where such industrial chemicals are legitimately necessary to use, inputs and outputs can be measured, and detection taggants[1] used, and many other security measures, to prevent accidental or deliberate loss of control over such chemicals.

[1] https://en.wikipedia.org/wiki/Taggant#Explosive_taggants