Excerpt:
Most major subreddits show a decrease of between 50 and 90 percent in average daily posts and comments, when compared to a year ago. This suggests the problem is way fewer users, not the same number of users browsing less. The huge and universal dropoff also suggests that people left, either because of the changes or the protests, and they aren’t coming back.
Looking at the subreddit stats data it honestly looks more like automation died when the APIs were killed. You can see just a clean drop of 75% on July 11th. I don’t think that was all of the content creators suddenly dropping it on the same day. There were so many reposts and botnets that were reposting comments from imgur and old reddit posts and whatever on the big subs that I totally believe the organic traffic on reddit is sub 50%.
That being said I believe that the big hole that automated content filled (resurfacing vast amounts of the most engaging content) will really hurt engagement of humans and the humans will lose interest over time.
You have to remember that APIs were used massively by third party apps users.
I don’t see a reason to attribute the API related drop more to automation than users stopping browsing reddit because third party app ban.