Google claims it has no idea how many people switch the default search tool on their phones and browsers.

A key part of Google’s argument is that it’s easy to change your default search engine, but of course, that requires knowing it’s possible and caring enough to make an effort.
Judge Amit P. Mehta asked Google’s Schmidtlein how many people change the built-in search engine on Firefox, in which Google pays to be the default option. Schmidtlein said “droves” of people switch, but said Google has no idea how many people make the change. Answer: we have no idea. At a company built on data analysis, that’s a tough sell.
Schmidtlein said there’s no reliable data on that question, and even if there was it wouldn’t be accurate because people can just switch back.