PageRank was a huge deal, and drastically increased the quality of the results over previous approaches. They absolutely disrupted search.
Google was founded in 1998. AdWords came out in 2000 and the company had its first profitable quarter in 2001. Three years isn't bad to build a tech company that can turn a profit.
They are an ad company first and foremost. Search, Android, Chromebooks, browsers and Cloud hosting all just feed their machine.