I agree that it is still worthwhile to do what you can. If large numbers of people stopped using just Google search and gmail, Google would most definitely not

I agree that it is still worthwhile to do what you can. If large numbers of people stopped using just Google search and gmail, Google would most definitely notice and feel it hard. Or to phrase it differently, the choices of individual users absolutely can still decide the fate of these companies. This sounds obvious, but is not always true (it would be much harder for individual preferences to dethrone Microsoft, for example).