I even logged in using incognito mode, using both Firefox and Chromium without any adblocker and I still didn't see anything except for posts by friends (and a few ads of course).
Perhaps I'm not getting anything else because I rarely log in, so they are hoping to get me back in by showing me stuff that I'm more likely to want?
This doesn't do what you think it does.
When you go to facebook.com incognito means you wont give them any of your normal cookies so facebook will be all like "Who is this guy???"
But then you log in, so facebook goes "oh I see it's lokedhs! welcome back!"
Incognito mode is designed to be undetectable. So from Facebook's point of view it looks like you signed in just like normal, and they will give you content just like normal.
Sorry for not being clear about that.