Do americans really get that much spam? I don't see the point of this. You can unsubscribe most superfluous newsletters anyway and you have a spam filter. A few intelligently chosen folders and inbox zero is a piece of cake.
For work email, various salespeople reaching out to sell things, often things completely unrelated to my job title, are highly annoying. I report all of them to spam to Google and block their emails, but the approaches of modern salespeople are increasingly indistinguishable from those of mass spammers (burner domains, "prewarming", multiple scheduled human looking followups, etc.)
Things I do intentionally subscribe to (such as airline offers) tend to switch their send-from address or title or something else every so often and are no longer caught by filters. At some volume, this becomes an occasional annoying toil to deal with. Note, I don't use Gmail, unlike ~90-95% of people in my circles.
I used to try to manage it with filters and unsubscribing and such, but at some point I realized I go years at a time without receiving emails from a human. My actual usage pattern was that I only looked at it when I expected an email from a machine, in which case it'd either be in the top 5 or so messages, or it'd be the first hit or two for a naive search.
Now I just let it fill up with shit, because who cares? I basically never open it without a specific message in mind, anyway. Trying to manage it was a total waste of my time.
Honestly, I think it all comes down to discipline. You should immediately unsubscribe if you do not want someone’s newsletter.
But my problem is different: I get a lot of emails that I do want to receive, but I do not need to read them right away - or sometimes never. For example, mortgage monthly statements, which I really only need at tax time.
I now have another address that I am much more restrained about sharing.