Personally the amount of junk I get has been drastically reduced post-midterm election. Somehow I got onto an ultra-right wing MAGA spam list, I was getting 4-6 messages a day telling me to support Ted Cruz or give all my money to some random fascist on the other side of the country. It was horrible. I would report every single one via this. No idea if this feature also helped cut down the spam but it feels good!