If Godzilla turned up at a city gate, the guards wouldn’t bat an eyelid. People can deal with the monsters. It’s all the other stuff —phantasms, storms, demons and all the unknown they’re terrified of.
Take the Wrecking Woods for example. It sprouted up west of the city and has been expanding ever since, colonizing the countryside with its deadly vegetation. Nobody knows how to stop it. And nobody knows much about what’s in it.