There should be an option at the post office to opt out of any/all advertisements. Ive thrown away at least 100 pounds of useless mail i havent even opened because its like “Use our credit card! Vote for the Nazis! The person who wants free healthcare did one bad thing in 2006, but its actually totally reasonable in context! Remember 4 years ago when you tried a food service? Do it again!”
I think paper usage would go down at minimum 10 tons if this type of mail was outlawed
In some European countries we can put stickers on the mailbox which indicates if you want to receive ads or magazines (like from shops with discounts). It gets mostly respected afaik.