I would argue in this narrow case - I would not point to nefarious undercurrents. Google's ML mail spam models are that way because there's too many bad actors. Email, even in 2019, still extremely valuable. If you can get into people's email inbox, there's still quite high conversion rate - better than clicks/videos on a pure percentage basis. Even the author wants to reach out to people in a cold fashion. As a gmai…
We[1] run our own mail and DNS servers and, as you might imagine, have never sent a single HTML email or any email with any kind of "element" in it, etc.
Just plain, ASCII text.
We've got a 15 year clean IP, perfect score on the "mail config checkers" and almost every single email we send is in response to an email from that sender.
And yet ... often enough to make me anxious, we get marked as spam.
[1] rsync.net