[digitalixus]

That's because Glassdoor can be full of crap; it was useful a few years back but now it's flooded with HR spam that are fake reviews and damage control, and presumably a few fake salaries thrown in as well. Most salary numbers there seem to be posted by entry to mid level employees as well. Rarely ever do people from higher levels or getting paid a lot go on there to post what they make.

Glassdoor can be relevant for American salaries thanks to the sheer quantity of figures being posted, but I've found salary fields to be sparsely populated for Germany (where I live now), and a few European and Asian countries I've checked out. It's kinda dangerous in the sense you could look up figures on Glassdoor and 9 times out of 10, you'll end up lowballing yourself if you try to negotiate salary IRL based on what you saw there.