The lines between Google "watching the market" and Google "commanding the market" are very blurry. If you don't get featured, nobody knows that you exist, nobody links to you, you don't get featured. Otoh: if you get featured, everybody sees you, people link to you, you get featured.
Today Google is the tail that wags the dog and a purely popularity based algorithm is more concerning.
However it’s also unquestionably true that Google results are not purely a popularity contest, and then the question becomes whose hand is on the tiller and which way is it steering?
Clearly in this case it is steering towards mainstream media outlets which all slant a particular way. This does not have a small impact.
It's like saying Burger King offers "the best" food, because it's popular.
And there's not really a reason(besides a little bit of money) for Google, The global monopoly, to insist on doing that. It's not that hard to have an easy option for quality content.
For example: Google's forum search, which was cancelled.
Not really; no-one goes to Burger King because they think they are getting the "best" food. They think they are getting convenient, affordable and quick food. You certainly could argue that Burger King is enormously popular because it is very good at offering those three attributes.
You can observe that an objective unbiased media source in any realm with a biased and obfuscated view of reality would do less well relative to one that catered to that biased and obfuscated view of reality, which is why media sources even in the modern age are localised and tailored to the audiences which they are aimed at, prejudices, unfounded beliefs and all like MEMRI in the middle east, christian fundamentalist media like WND, etc. If you expand the scope of enquiry to all of possible human history you can very easily imagine that the media sources which would and have historically done best in the more ignorant periods thereof are obscenely biased and not at all "the best content".
If you think that BBC / NY times / WaPo ad et al are not guilty of the exact same kind of thing merely from a different perspective, well that's quaint and charming, but simply completely inaccurate. Nobody has the full story, everybody is wrong, and putting together the puzzle pieces on any issue requires extensive survey of a broad variety of perspectives and sources, and even then, you're going to fall victim to your own biases and simply become another part of the tapestry to boot.
There is no winning. There's just losing less badly.
And it so turns out that finding and surfacing the best content aligns well with the number of people who link to that content, which creates a great product for Google, which aligns with Google making a profit.
You can't argue from a hypothetical where Infowars offers the best content, as Infowars doesn't offer the best content. If Infowars started offering better content than BBC, people would start linking to Infowars, and Infowars would rise in the search results. It's not Google's fault that a lot of Infowars content is low quality that people don't link to.