I was on reddit for a very long time. And this is why I started to bemoan when communities would celebrate that they passed some number of subscribers.

/pardon me as I yell at the clouds. Stop now unless you want to read a completely unnecessary rant.

Two of my favorite niche subreddits were absolutely ruined by getting big: mindfulness and foodporn. The former was primarily a discussion about practicing mindfulness, there were even a couple of buddhists who actually deeply studied the tradition that provided very good non-western insight. It was a good place to go get help, albeit occasionally got a spattering of stupid memes, but you could easily get past them. As it grew it turned more and more into just memes, and then was just over-taken by new-age nonsense and pseudointellectual quotes over pictures. Food porn (while never exactly what I wanted) went from often having well-done pictures of good food, to shitty cell-phone shots of oversized hamburgers, half eaten food, and plates of food sitting on counters with all of this shit in the background.