> Pornhub had a large blogpost claiming that thye are better at filtering illegal content than facebook, and that the latter has many times greater problems with illegal content

Facebook is also orders of magnitude larger and has to deal with content that blurs the line between legal and illegal. It's a significantly more difficult task.

> has to deal with content that blurs the line between legal and illegal.

All of Pornhub's content blurs the line between legal and illegal, depending on the jurisdiction. Every single piece of content they deal with.

Go look at some amateur porn featuring a supposed 18 year old. Is she actually 18, or could she be 17 thus making it very illegal child porn?

That's a pretty freaking blurry line.