I tried it with r/fifthworldproblems, a dark surrealist sci-fi subreddit where you couldn’t reference existing canons. Ideally the goal was to have an evolving idea of something new that didn’t fall back on stagnant ropes. In reality, there are three kinds of people in this world:

1. Me, precious

2. People who are poisoned by Lovecraft Brain

3. People who see an existing idea and latch onto it without yes-anding.

The first group is fine. Always quality, never had any problems, easy on the eyes. It’s the second and third groups which made that idea and r/seventhworldproblems go to shit within a year. Unless it’s rigidly controlled like SCP, most of the people participating just want to write fan-fiction about the stories they already know. To most people, “dark sci-fi” just means Cthulhu doing that one thing it does. Others see what works but not why so they just endlessly reference whatever original ideas emerged on the forum. Total decentralisation didn’t work at all and now there’s some reactionary goober beating the dead horse to deather. You need some kind of guiding force behind it if only for quality control, and people hate when you reject their post for quality control.