I stopped trusting Google the day they announced they would use Gmail email content for displaying ads. Sometime in the late 00’s it was I think.
Here's an article from June 2004:
https://www.theregister.co.uk/2004/06/15/gmail_spook_heaven/
The privacy implications were widely discussed when Gmail launched, but then the media interest just faded out because people were apparently OK with it and Google promised to "do no evil". So here we are, 14 years later.