Stack Exchange questions / answers will rise in search engine rankings faster than threads on forum.cardano.org because the stack exchange network is large and contains a lot of cross links.
So, even if forum.cardano.org has all the same features, having a stack exchange site might still be good for "popularity" effects.
There is a slack channel for Cardano developers
I think many of the members would be interested in this proposal.
There are many topics relevant to cardano. When looking at existing questions, it becomes clear that those are mostly development-related, simply due to the technology related exchanges they are posted on.
When looking at other websites and communities we see that many questions are less development-related, yet still technical in nature. Due to the lower ...
There's a Stack Exchange site dedicated to Information Security; it covers both the technical part of hacking and ethics. See e.g. How do we provide value to white and grey hats? and related questions on their Meta site.
As of 20 March 2021, There are 276k members in Cardano subreddits 5k members in Cardano Developer subreddits, 5K plus members in the pool operators telegram channel, and 50k plus members in Cardano telegram channels. A substantial number of technical questions are raised in these channels and get answered. Being an open-source project with multifaced high-...