What historical evidence is there for this? In every case I can think of in which a Google product supplanted an established competitor, it's been pretty clear

What historical evidence is there for this? In every case I can think of in which a Google product supplanted an established competitor, it's been pretty clear that it did so through merit. As a converse example, I don't see Google Finance establishing any obvious position of dominance. Google has had no lack of failed products.