There are and have always been lots and lots of options. It's up to the publisher to decide who they work with. But with the scale that Google holds, it's hard

There are and have always been lots and lots of options. It's up to the publisher to decide who they work with. But with the scale that Google holds, it's hard to compete with their money as they own the market and have a black box monopoly - there is no way to know what the actual floor of the bid is for instance, its set by Google, arbitrarily. In other words: They say it costs $5 per click or $25 CPM, they just make that figure up. There is no real market driving that cost. It's 100% made up to maximize Google's profits.