This is the reason why open ad exchanges, which are slowly dying because of the Facebook/Google duopoly on inventory, are a better solution to avoid conflict of

This is the reason why open ad exchanges, which are slowly dying because of the Facebook/Google duopoly on inventory, are a better solution to avoid conflict of interests from monopolistic entities. But it comes with privacy implications that are not acceptable to most (ie share cookie data across more players than the 2 aforementioned companies).