One benefit I find to mailing lists is that they are search engine
indexed, meaning when I google a warning or assertion error I often get
pointed to a mailing list thread that discusses the issue I am trying to
fix.
Being able to find such discussions and then follow them in thread
format is very valuable and saves quite a bit of time. I haven't used
Discourse so I don't know what the state of such a workflow is --
apologies in advance if this use-case is a non-issue.
Discourse has fully searchable archives, and allows indexing on Google, so you'd very likely get more relevant results with it than with generic Google searches.
Emmanuele.
