There is an obvious problem here - companies who don't advertise with Google could easily find themselves blocked from appearing on the first pages of Google search results. Would anyone really be surprised to find that the internals of the Google search algorithm have a weight factor that assigns better scores to sites that advertise with Google? Hence requiring Google to expose the internals of the algorithm to public scrutiny really seems like the only way forward. Yes, those are 'trade secrets'. So are the contents of your favorite hot sauce, but government regulators require those contents to be displayed on the product label (for good reasons).
On top of all that, Google's also under pressure from governments and media corporations to push their information content (aka propaganda, influence, etc.) to the top of search results, burying anything like independent content in those areas (world events, domestic politics, etc.) far down. This is particularly obvious on Youtube incidentally, but Google has the same problem. Some of this can be avoided using the 'verbatim' option and some interesting word choices in your search string, but it's a fairly tedious exercise.
Again, exposing the internals of the Google search algorithm would be interesting here, as it seems clear certain 'authoritative sites' are assigned better scores in the search ranking - not because they have more backlinks or more accurate content, but merely because of governmental and media pressure.