I believe that becoming a Hero Member is not a matter of time.
You must know your purpose in the forum. 2-3 or even 4 years will not become a Hero Member if the goal is only to participate in the bounty campaign. I've seen many accounts that have been around for some time on forums with such a purpose. make thousands of post report bounty. without any merit. no matter how much activity and how long they were on the forum, they would not become a Hero Member.

as I recall, there is a thread showing the ranking of newbie accounts having thousands of activities. I forgot where to read it.