> then Google of 15 years ago would have found it and put it on the first page.

I don't think Google of 15 years ago will do a good job on the current age of internet. The size of web has increased a lot like 100x where most of the increment comes from unstructured formats like video or image and its signal to noise ratio deteriorated considerably. SEO has become much more sophisticated ever. A large fraction of useful information is now locked in the unindexed walled garden.