A shotgun with a rifled barrel is very accurate. 100 yard shots are pretty easy with one or two magazines of practice. Anyone who thinks they can shoot more accurately with a pistol than a shotgun equipped with a slug barrel is seriously deluded. Especially when you add sabots into the mix. You are basically shooting a low speed 50 caliber rifle. Modern shotguns come equipped with decent sights.
The only time a pistol is better than any long gun is when you can't get your long gun.