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FWIW, https://myaccount.google.com/activitycontrols to control what data they'd use and how it's used, and http://history.google.com lists the data they've collected. You can delete some or all from there.

I highly doubt it and derived data are actually deleted, it merely stops you from being able to view it.

That's a pretty serious claim. Do you have anything other than scepticism behind it?

[Disclaimer: I work at Google. Every team I've interacted with takes this very seriously]