Whether this would effectively completely block all unwanted email, is the question.
My idea is, whitelist only what you want to get from those you choose, be it your contact list or even just a few friends who like to do things together, to a dedicated mailbox.
Not like Facebook, where you share you stuff with your friends and not the public, but still with Facebook and all it's customers. An adhoc social media platform. Members only, by invitation. No login, password, etc. Lke a private party.
I'll take my answer off the air...
...because I noticed that the sign in to the Forum involves having one's username displayed. It's a public forum. Maybe that's not necessary to have my username displayed on the Forum? I'll change it after I'm done. Maybe Google et al has a bot scraping this discussion .