I think it's important to realize that search engines both bring websites to people and people to websites. The genius part of Google's position in the market is that they both sell ads, and then direct people to the places where the ads are sold. This is also a major contributor to their search engine spam problem; they can't well penalize ads without undermining their core business model.
Although I don't think any search engine has ever indexed or will ever index everything. That doesn't really make sense. Realistically I think maybe 1% of the documents online are ever going to be a good search result for any query ever.
Internet search is all about being judicious about what you index.
>>> I think it's important to realize that search engines both bring websites to people and people to websites.
I don't disagree with this, I was simply pointing out that Google makes no money by sending people to a web site unless the owner of that web site has bought an advertisement and the person involved has clicked on that ad. Organic search, like "good explanation for approximation theory" should have something like this: https://xn--2-umb.com/22/approximation/ as one of its top results but it doesn't even make it to the first page.
Although I don't think any search engine has ever indexed or will ever index everything. That doesn't really make sense. Realistically I think maybe 1% of the documents online are ever going to be a good search result for any query ever.
Internet search is all about being judicious about what you index.