Shakers in the 18th century made some of (in my opinion) the most beautiful wooden furniture with simple hand tools. But each piece took ages to produce and finish.
Now we have power tools and inexpensive stains and finishing products that dry quickly. The output of a legion of Shaker craftsmen can be matched by a single moderately skilled woodworker today.
Similarly, the fact that attacks were successful without drones doesn't mean that cheap, commonly available drones can't make it easier to do lots of damage. Nobody says you need these items to make a successful attack, just that they have the potential to make a bad attack much worse. Not to consider this while implementing countermeasures is irresponsible at best.
Leaving the bags is arguably easier to do.