[snarkpup]

These companies (including zillions of small surveillance capitalists) are lurking under the hood of most modern websites. (For a list of some of them, install uBlock Origin or some similar browser extension and look at what it's blocking.) Email sent from point A to point B may go through Google servers on the way. This is more than social media. You would have to stay off the internet, go totally cashless, etc. to avoid this stuff.

[snarkpup]

Correction: go cash only.