Really, now.
Funny how I can, and do, go to places not even found on Google searches.
It's almost as if your statement isn't supported. Besides, are you telling me that the ascendance of Google had nothing to do with its superior technology, and is all just a government plot?
Google and Yahoo do not control what you see but they do control what comes up when you search for something
For example, if you search for a certain banned drug that kills mosquitoes, you will have to go through 50 articles supporting the banning before you will find anything on the number of deaths in third world countries from malaria that directly relate to the ban.
Also, they can be bought ... so if you search for, say, cancer in dogs, you will be sent to sites proclaiming all sorts of miracle (and expensive) cures.
However, it is a wonderful thing and can be navigated to good sources if you have the patience.