Comment by einpoklum

Both Apple and Google guarantee you a total _breach_ of your privacy: They are known to share most or all of your data, that's on their servers / comm lines, with branches of the US government, en masse, pursuant to agreements or compelling arrangements. This is the PRISM program, revealed last decade by CIA whistleblower Edward Snowden.

As for other uses of your data, and what they "send back home", there you might be right about the differences between Apple and Google, but I would again not put faith in either.