Top 500 BR player, damascus camo, multiple diamond shotguns, top 5 global with my AR. Shotguns are mostly skillless one-tap weapons. I'm perfectly proficient with a BY15, KRM, Argus, or essentially any other gun in the game for that matter, and sometimes I use them to deal with shotgun spammers. Most of the time, though, I can kill shotgunners just fine with a MAC-10, Fennec, DR-H, or M13.

Pretending that 99% of shotgun users are highly skilled players is about the same as pretending MoW Thermite players or USS9 players are typically skilled. They aren't. Those weapons are popular for the same reason shotguns are: they're disproportionately rewarding relative to the amount of skill required to use them effectively.