People get jumpscared by house centipedes because they have like one of the fastest land speeds relative to body size among insects, or a lot of mammals, moving about 16 inches (40.6cm) a second, that's why they sometimes seem to appear out of nowhere. Like if you have a ten foot ceiling, a house centipede can go from the floor behind a bookshelf to the ceiling in the time it takes to catch up on your tumblr feed. And they're pretty harmless but also they are wildly overconfident in their ability to hold onto a ceiling.
The tags are sending me
If you aren't allergic, house centipede venom is about on par with something like a yellow jacket or garden spider, somewhat painful but zero medical significance. You'll get swelling and that's about it.
But! That's if their stingers can even get through your skin. Very few house centipedes' stingers develop the size and sharpness to get through your skin - if one even wants get close enough to sting. The average human is basically Godzilla to a house centipede, they don't see us as something they can survive, so they would much rather run away or try to be hidden. But they also have kinda dogshit eyesight so we probably look like part of the landscape until we move.
And of course the old addage - venom is expensive. They don't want to waste the calorie cost of making venom on stinging something where the sting won't help survival and won't feed them. They're startling when they appear but they are well and truly harmless. Or if you live in a city and have pest insects, pretty beneficial.
You see them in the shower and bathroom so much because damp environments help them breathe. They have open spiracles to take in air, just holes along the surface of their bodies (you can see them in close ups sometimes). They're a very primitive design by most standards, and if they're somewhere too dry, they can't get air, and might even just dry up and die. Since your bathroom is the wettest, most humid place in the house, if you have them around that's where they'll go to relax and recharge before another night of hunting down every last cockroach in your apartment.
There are some much larger centipedes that can be more dangerous to get bit by, but not the humble house centipede. He's just a little freak tryin to get by, it's not his fault he's clumsy and looks like a facehugger for a barbie doll.
