My first impulse would be to ask ChatGPT, because questions like that have worked in the past. Now it appears to refuse to provide any information related to any online forum, even if you specify a pre-2021 timeframe.

The next best thing to do is just to read stories that interest you and click the 'comments' link in the profiles of the authors of comments that seem insightful to you. This can lead you not only to interesting users but interesting threads that you missed the first time around.