Right - until anti-air measures designed to deal with voluminous relatively low performance threats get deployed. There's a reason Ukraine has been rolling out old school anti-aircraft and flak guns, and the modern variants are now starting to be produced - i.e. area effect microwave weapons and high energy lasers. Systems which aren't very useful if your adversary is highly capable, but which are effective if your adversary is relatively fragile. Again: volume turned out to be relatively useless in WW1 when the adversary had well placed machine guns.

But it's also an apples to oranges comparison: THAAD is in no way designed to intercept drone threats. The story here is closer to the US started a fight without actually investing in the sort of defenses which would deal with it - i.e. with a rack of Ukranian interceptor drones as part of the air defenses, the THAAD radar likely makes it.