I was going to comment I've never seen this before. Then I went to a subreddit and it hit me that I only use old reddit, which lacks the "best" feature.

I'm not sure why people tolerate the new reddit website. It is so slow, busy, and chock full of ads. When I open it on the phone you are straight up missing a lot of discussion comments, so it is broken too. You click a comment it looks like it has no subcomments under it. You click the permalink opening that comment thread in a new window, and there's still no subcomment under it. Now you prefix old. to the url, now you see the subcomments.

Makes me wonder how much discussion there is that is just not observed at all by a good fraction of the site who browses these same threads. Two universes on the same post.