I think it solves a business problem rather than a problem that consumers necessarily feel. Google have good reasons (lessen effects of SEO & boost ad impressions) for not wanting all of their traffic to go to the very top results or the first page.

Infinite scroll encourages users to keep going. It's similar to how certain demographics will scroll through Pinterest for hours. It removes the boundary where someone might say "OK, that's the last page I'm going through."