I agree wholeheartedly in principle, but the reality is that it's nearly impossible to escape Google getting their hands on yours and your correspondents' messages at some point. So many businesses (and third party email providers!) use Google's services on the back end, and many relays out there are owned by Google/Alphabet even if it's not readily apparent, that the only way to even attempt to avoid them is using encrypted email. Unless everyone you communicate with (including companies, governments, and other organizations) is willing to only communicate via encrypted email as well, it's a lost cause.