Reporting phishing emails in the junk folder

You still can if you wish:

Recognize and avoid social engineering schemes including phishing messages, phony support calls, and other scams - Apple Support

In most cases the spam you receive in the Junk folder is from spoofed sending addresses and not likely to be repeated where reporting has little effect. The spammers also use throwaway account that are easily created without any identification that can be tracked. They can create an account and send out thousands of emails, delete that account and create another one to do the same thing. Blocking or Reporting the first account does not prevent future emails from that same spammer.