Well, I know of a few big tech companies on the east coast do this so that they can attract higher-level devs and then say after the super-long interview proces

Well, I know of a few big tech companies on the east coast do this so that they can attract higher-level devs and then say after the super-long interview process "sorry, you're actually a mid-level dev" or even try and convince them they are a junior. It's a way to get around salary disclosure laws, as well.