I think your premise is wrong.

- People don’t fight spam. I rarely if ever get spam in my email. Spam filters work well enough. Whitelisting is also available. Most all email clients support smart folders that contain emails only from contacts.

- Email IS private. Privacy =/= E2E encryption. Other people cannot read my email. My friends and business competitors cannot read my email. Providers can, but are incentivized to not read their customers’ email, otherwise they would go out of business.

- PGP does work. Most people don’t need it.