Is that the whole story? Why isn't reddit overrun by bots then (or are they?), and why wouldn't basic proof-of-work techniques fence against bots? Since they started out just in January, isn't it plausible to assume they didn't meet their target user figures and investors jumped ship?

Go to any career subreddit and it's almost entirely LLM- generated rage bait. Never mention political subreddits, those have been gamed for years.

Reddit very much is.