You're basically saying that in certain cases Google's AI is better than you because a) it has access to all those adwords and b) it's ALGO is faster/smarter than you might be.
What you are neglecting to mention that Google takes up a very large percentage of the action in order for you to use their AI. So while I grant that you are right in certain circumstances the AI is *smarter*, I think there are very few and very rare occasions when it that much smarter and efficient that it warrants the big fee that they charge you.
Here's an example: I pay my affiliates the same thing it costs me on Google to aquire a customer. AdSense advertisers advertising my AdWords products are only getting ~40% of what they could be getting if they went to me directly.
I personally don't think it would be that hard to gather dozens of relevant affiliate links, put them in a mysql database, and feed them out on to your pages in a way that meshes well with your content.
Kind of like AdSense but using your own grey matter.
This is an easy one. I didn't say this (so, not a straw man), but I suppose I am assuming it as a basic law: there is only so much room on any web page for Ads.