Just like Microsoft did in the 80s/90s, Google has created some awesome products. At some point, it stops being worth it to compete and way easier to leverage existing strengths. For example, any product that relies on Adwords sales, Google can bid infinitely high and take the top spot. Or in the case of search, just putting their widgets in at the top like they've done for flights. It stops being about creating a better product and only about creating a winning product. Competition is really hard and risky. Owning your competitor's sales channel and then pushing them out is so much easier. Google now seems to be crossing this line.