Google have found a sweet spot where their search results are almost correct but still insufficient.
That "near-correctness" ensures you don't lose hope of finding what you are looking for, so you keep reading result after result. And most of those sites are conveniently loaded with ads, sold by guess which company - Google!
Eventually, pagerank cashes out, and you find what you are looking for. You receive a much needed endorphin kick, and you go on with your day. Rinse and repeat.
I would bet a large amount of money this is the correct answer.
It certainly is the approach facebook has taken with their marketplace place search engine, where the signal to noise is just barely high enough to keep the audience and there is absolutely no tooling exposed (verbose search etc) to increase the signal rate.
That "near-correctness" ensures you don't lose hope of finding what you are looking for, so you keep reading result after result. And most of those sites are conveniently loaded with ads, sold by guess which company - Google!
Eventually, pagerank cashes out, and you find what you are looking for. You receive a much needed endorphin kick, and you go on with your day. Rinse and repeat.