PER identical projectile ie.. The force between a .410 and a 12 gauge is identical. a single pellet of 00 buck from a .410 with strike with the same force as a single pellet from a 12 gauge. The pellets weigh the same(mass) and are travelling at the same speed(speed)... Mass x speed = force. So, each projectile will have identical penetration. The felt recoil on a 12 gauge is more because it has more OVERALL force. That's why a .410 can't produce near as wide a pattern with shot(which is useful for bird hunting) or use near as heavy a slug(which is useful for larger game hunting). However, it is generally agreed that Buckshot is the best choice for home defense. If a single round of 12 gauge with 10 balls of 00 buckshot is the gold standard, then my three rounds with 15(5 each) balls(which have equal penetration) is easily just as lethal.
More importantly, a single round of .410 ammo is infinitely more lethal than the zero rounds of 12 gauge ammo which my other household members are willing to fire. I can't always be home to protect my family. I need a weapon that everyone can use.
Yes, Buckshot isn't allowed for deer hunting in many areas because it is a poor performer(inaccurate). That's also because people hunting deer usually take shots from greater than 15 yards... and aren't in their living room. If I did shoot a deer in my living room I would probably get cited for baiting them.