I'm not sure I understand the question. It's up to each publisher to decide if they make enough on AdSense to justify putting its ads on their site. The success of Google's ad business suggests that even net of fees, many people still think it's worth it.
Now, personally, I don't think Google pays me enough to run AdSense on any of my sites. It's frankly not even close, so the fee isn't the issue -- it's just a bad fit for the volume and type of content I produce. I can see why it's great for many other publishers though.
Well, I understand an organization that sets up a network where content creators get paid incurs some costs. I was curious as to what people think is the appropriate amount of fees they should charge for that service.
Google's costs and fees are irrelevant to the content creator. They want the ad network that writes the biggest check each month, not the one with the lowest operating overhead.
In fact there are many niche ad networks with fees much higher than Google, but they actually pay publishers more because they also charge the advertisers much more.
Nothing destroyed the quality of web content as much as AdSense did. So many websites turned into "made for AdSense" and started doing stupid things that actually severely reduce their earning potential.
Now, personally, I don't think Google pays me enough to run AdSense on any of my sites. It's frankly not even close, so the fee isn't the issue -- it's just a bad fit for the volume and type of content I produce. I can see why it's great for many other publishers though.