I have been thinking about the same problem since a few weeks. The real problem with search engines is the fact that so many websites have hacked SEO that there is no meritocracy left. Results are not sorted based on relevance or quality but by SEO experts' efforts at making the search results favor themselves. I can possibly not find anything deep enough about any topic by searching on Google anymore. It's just surf…
Many websites do have "hacked" (blackhat/shady) SEO, but these websites do not last long, and are entirely wiped out (see: de-ranked) every major algorithm update.
The major players you see on the top rankings today do utilize some blackhat SEO, but it's not at a level that significantly impacts their rankings. Blackhat SEO is inherently dangerous, because Google's algorithm will penalize you at best when it finds out -- and it always does -- and at worst completely unlist your domain from search results, giving it a scarlet letter until it cools off.
However, the bulk of all major websites primary utilize whitehat SEO, i.e "non-hacked," i.e "Google-approved" SEO to maintain their rankings. They have to, else their entire brand and business would collapse, either from being out-ranked or by being blacklisted for shady practices.
Additionally, Google's algorithim hasn't changed much at all from pagerank, in the grand scheme of things. If you can read between their lines, the biggest SEO factor is: how many backlinks from reputable domains do you have pointing at your website? Everything else, including blackhat SEO, are small optimizations for breaking ties. Sort of like PED usage in competitive sports; when you're at the elite level, every little bit extra can make a difference.
Google's algorithm works for its intended purposes, which is to serve pages that will benefit the highest amount of people searching for a specific term. If you are more than 1 SD from the "norm" searching for a specific term, it will likely not return a page that suits you best.
Google's search engine based on virality and pre-approval. "Is this page ranked highly by other highly ranked pages, and does this page serve the most amount of people?" It is not based on accuracy, or informational-integrity -- as many would believe by the latest Medic update -- but simply "does this conform to normal human biases the most?"
If you have a problem with Google's results, then you need to point the finger at yourself or at Google. SEO experts, website operators, etc. are all playing a game that's set on Google's terms. They would not serve such shit content if Google did not: allow it, encourage it, and greatly reward it.
Google will never change the algorithm to suit outliers, the return profile is too poor. So, the next person to point a finger at is you: the user. Let me reiterate, Google's search engine is not designed for you; it is designed for the masses. So there is no logical reason for you to continue using it the way you do.
If you wish to find "deep enough" sources, that task is on you, because it cannot be readily or easily monetized; thus, the task will not be fulfilled for free by any business. So, you must look at where "deep enough" sources lay: books, journals, and experts.
Books are available from libraries, and a large assortment of them are cataloged online for free at Library Genesis. For any topic you can think of, there is likely to be a book that goes into excruciating detail that satisfies your thirst for "deep enough."
Journals, similarly. Library Genesis or any other online publisher, e.g NIH, will do.
Experts are even better. You can pick their brains and get even more leads to go down. Simply, find an author on the subject -- Google makes this very easy -- and contact them.
I'm out of steam, but I really felt the need to debunk this myth that Google is a poor, abused victim, and not an uncaring tyrant that approves of the status quo.