I guess talking to people and making friends helps. Online, maybe seek out discords and befriend people and they may tell you. Not unlike how you find cool underground clubs.
You can also just kind of hop from blog to forum to subreddit to discord to social media account etc. passively over time based on what interesting people are talking about or mentioning. My main point is that you can't expect to find a list of good pockets of the internet with low effort, because if they are low effort to find, they will be flooded and made not good.
alex_suzuki|14 hours ago
johnnyanmac|6 hours ago
bonoboTP|6 hours ago