I also have been forwarding every single spam to abuse@icloud.com and reportphishing@apple.com, every day.
I have seen neither a reduction nor an increase—I get between 100 and 150 per day.
I CONTINUE to have some of these junk mails—including some for which I have written a specific rule to forward to above reporting email addresses and then divert to a different folder—show up in my inbox, which is infuriating. (The ones that are subject to the rules are particularly irritating, since the rules I have made work much of the time. So why don’t they always work??)
ALSO, I regularly find legit emails in my Junk folder, including a utility bill (one of two from the exact same power company, sent at almost the same time, for two different homes!), a flight reservation from an airline I fly with regularly (seriously!!), and various newsletters I am subscribed to that have been going to my inbox for many, many years. To me, this is inexcusable. I understand if a new sender gets diverted to junk, but when these kinds of mistakes occur, it makes me wonder.
I am envious of those who are seeing a decline… here’s hoping it is a positive development although I am not holding my breath.