Why Are Mummies Considered Scary?

Mummies were often the stars of horror films in the black and white days, since then there haven't been as many mummies in movies aside from "The Mummy". What I'm wondering is why mummies were ever scary to begin with. They are technically Egyptian zombies, but they're also completely wrapped up in cloth. If they pulled the cloth off and walked around naked then I could see being creeped out by that. No one would want some old ass leathery skinned freak coming after them, that's exactly why I don't visit my grandma at the nursing home anymore. You're old your bones are half dust, if you come near me I will just kick your legs out from under you and smash your skull in! I mean that about mummies, not my grandma by the way.

On top of that, mummies are all slow and dumb. There's no such thing as a fast mummy the way there are those fast zombies in newer movies. You never see a mummy sprinting like a track star. Even if they could they'd probably get tripped up by their feet wrappings. Then let's say a mummy actually does get its mitts on you. What's it going to do? What does it even want? It can't eat your brain because its mouth is covered up and it has no teeth. Would it snap your neck or something? It doesn't seem like mummies have the dexterity to do that considering they walk around with their arms extended out with very little range of motion. Maybe there's something I'm missing here, but mummies have never frightened me. They're just elderly Egyptian people and folks need to stop being so racist towards them and give these bastards a chance!