For a decade or~so I subscribe to newsletters and had skip inbox rules that archived them in a folder about the subject. Eventually I never really looked at the folders but it never bothered me as I don't really see them. Not sure if that means it works or not.

Hahaha it could well be that people are merely hoarding newsletter emails. I hope readers derive _some_ value from the emails, but since I'm not doing it to drive up "engagement metrics" I don't really mind.