Why are zombies so powerful?

It is said that to kill a zombie, it must be done in a very specific way. However, what makes them so powerful is that they are already dead. There is really nothing that you can do to them, other than put a bullet in one specific area. This could be harder than it seems, as there is no rhyme or reason to what they are doing. Outside of this “superpower” there is nothing spectacular about them. Zombies are, in and of themselves, on the lower rung of the horror chain.

The fact that they are already dead means that they are unable to feel pain. They have no human thought or emotion. Regardless of recent culture trying to “humanize” zombies, they are unable to achieve that emotion. To have any range of emotion or use of their senses, they would have to be alive. As zombies are “undead” they do not have control of their senses or be able to use them.