Some subreddits are/were highly toxic (e.g. the infamous r/incels). Some other are full of vulnerable life stories you won’t find anywhere else. People won’t post them on their public FB feeds; not everyone writes anonymous blogs. Any coverage of such topics by journalists (if the topic gets ever covered) is likely to focus on a handful of cases, be biased and heavily edited.
For an example from Reddit, see “Trans people of Reddit, what was something you weren’t expecting to be told, find out, or experience when going through your transition?” (https://www.reddit.com/r/AskReddit/comments/4g1pgu/serious_t...).
Another subreddit with not so much majority view is CMV: https://www.reddit.com/r/changemyview/. It is heart-warming (and mind-stimulating) to see people open to changing their minds. Compare and contrast with Twitter, where there are no enough characters to express a more nuanced argument. And views are usually pushed down one’s throat (if they ever leave a bubble).