The bigger and the more successful a forum/group/channel gets the more it attracts traffic. With more traffic comes more low-value traffic. Whether that is less

The bigger and the more successful a forum/group/channel gets the more it attracts traffic. With more traffic comes more low-value traffic. Whether that is less than or more than or quite exactly proportional I don't want to speculate about. If a forum gets too big, those who value lower volume higher quality traffic will leave. It often doesn't raise the level of the community remaining. Most clearly we have seen that with Stack Overflow. Where Stack Overflow is still useful as a "static" resource for questions/answers who have not changed for some time.