Sometime around the night of the DNC primary in 2015 there was a dramatic shift in the content on Reddit. If you were a frequent visitor of the homepage and /all at the time, you will know exactly what I am referring to. The product has gone downhill ever since. Comment search is nice because it enables users to find interesting content directly in the good niche subreddits.
I dug in there one time and found a fascinating obituary for a user on a subreddit for people living with addiction -- full of some touchingly personal and weirdly public stories. Following the user's profile from there taught me about the wild world of the "opiate roll call" subreddit (a thinly veiled Craigslist for drugs) which was at the time flourishing. Fascinating stuff.