I have always wondered if google can see the YouTube, Gmail passwords, not from the database,but you can see your own passwords in the browser in plain text and since all the apps are theirs, a keylogger would be impossible to detect.

Another thing is, do they have a back up of data from the Myaccount. Subdomain that users delete.

Still I trust google and amazon more than Microsoft and apple and Facebook. Just me personal view, I could be totally wrong. The ones I trust are simply more open about data storage and have less dark patterns and clandestine TCS. But yes, wide spread Gmail usage will make google see many things and they will collect a lot of data. Probably even more delicate data than what Facebook gets to see.