I use G Suite at work, and I wondered about this. From Google's modus operandi, I assumed they are mining data, for example, of all work emails to and from the accounts - and probably connected to my personal email addresses somehow, as part of a profile to target ads.
Is there a confirmation that this is not (or is) being done? I suppose, from a security/privacy perspective, it's safer to assume that it is, because it's technically possible.