I'm aware of that stuff. That's why I said "mostly". That stuff is bad, but only somewhat impedes the effectiveness of header bidding. There still is bidding going on, there still are many bids being won by companies besides Google, and there's only so much that Google can do about that even with these shenanigans. It's a far cry from all ads being sold directly through Google like on AdSense, where they can simply take a giant cut off the top and call it a day.