There's another side effect: Whenever a site or community grows, it becomes a more and more attractive target for bad actors. The site finds a way to separate signal from noise, this attracts an audience, and that attracts bad actors who learn to mimic the signal in order to access the audience for their own gain. Unless the site finds a way to expand whatever it did in the first place to isolate signal from noise, to also isolate signal from mimicry, then the site will go into quality decline.
We've seen it on Amazon with fake reviews and a flood of cheap crap, we've seen it on Facebook with clickbait, bots and manufactured outrage being counted as "engagement", we've seen it on Etsy with cheap crap passed off as homemade crafts, we saw it with StackOverflow-copying SEO-spam on Google, and just blogspam and SEO-spam in general. Whenever there's a commonly-relied-upon signal, there's someone trying to mimic it, thus lowering the value of the signal.
> Whenever there's a commonly-relied-upon signal, there's someone trying to mimic it, thus lowering the value of the signal.
Goodhart's law: When a measure becomes a target it ceases to be a reliable measure.
The other day someone was lamenting the disappearance of the downvote indicator from YouTube videos, which makes it impossible to use an up/down ratio as heuristic for quality. Sometimes the measure is so good that it's the custodians of the community themselves that become bad actors.
I believe the parent commenter did not mean that StackOverflow itself became bad, but rather that its content gets copied and cloned by bots and posted as much lower quality content on Google.
So I guess the critic goes to google content filtering algorithms then.
Quality overall dropped somewhat over they years (my subjective impression) but they grew by expanding to many different niches. They also skillfully connected them, so that each one feels like a tight community, yet easy to join.
We've seen it on Amazon with fake reviews and a flood of cheap crap, we've seen it on Facebook with clickbait, bots and manufactured outrage being counted as "engagement", we've seen it on Etsy with cheap crap passed off as homemade crafts, we saw it with StackOverflow-copying SEO-spam on Google, and just blogspam and SEO-spam in general. Whenever there's a commonly-relied-upon signal, there's someone trying to mimic it, thus lowering the value of the signal.