I discovered the forum pretty quickly after joining iNat, by clicking on one of the links on my homepage. Then I lurked for several months before actually making a forum account. My first post was in the topic How has Covid-19 affected your way of iNatting?, so I guess I joined the forum because I can’t turn down an excuse to share my personal experiences!
I like it a lot for the value of sharing knowledge to improve each other’s lives - on iNat and elsewhere. Recently I’ve been spending more time on the entertaining topics than the useful ones, though.