[potato3732842]

They are "being used" but shotguns are the last line of defense. Good luck stopping a little FPV drone with one. If you do not disable it by 50ft you dead. And you have like 10% odds. Way better than 1% odds you might have with a rifle or nothing but...

Jamming is first line of defense, a million times more effective FWIW.

[coretx]

One counter measure is no counter measure. If you look at toys like https://hackaday.com/2023/06/13/arduino-powered-missile-syst... and scale it up with bigger and stronger servo's for holding a shotgun instead of fake missiles; you'll have a second war - with the arms industry. For a bonus you'll also win the war of economy because the bill of materials costs less than a mad maxed FPV drone given you source the shotgun from the land.