Reddit drove away lots of users via that change, although I expect Reddit's MAU still grew overall due to the continued worldwide penetration of the internet. In addition, while in the short-term it almost certainly lost users, it drove the remaining users towards frontends that were more profitable to Reddit (i.e. away from the website and towards the app), so I expect the company still sees that as a win, at least as far as the IPO is concerned.
However, the deleterious effect on Reddit's overall culture cannot be understated. The people who were most driven away by the API changes were power users, and Reddit has become far more bland and repetitive as a result (to anyone familiar with the tenor of Reddit it may seem hard to believe that it could lower the bar any further, but I assure you, it has). The difference in trending subreddits from immediately before the blackout to immediately after was dramatic; whereas before you could expect the site-wide trending posts to have the nutritional content of cardboard (with the occasional gem from e.g. AskHistorians), it has been replaced with a flood of celebrity drama, ragebait from "unpopular opinion" clones, and ragebait creative writing exercises via dozens of similar "am I the asshole" clones. This is normalizing somewhat as the clones compete with each other and coalesce (Reddit's algorithm tries to limit trending posts to one per subreddit), but it's still a regression.
That said, it's still not the worst that Reddit has ever been; that title still belongs to back to 2016 when TheDonald popularized how to game the trending algorithm via brigading their own stickied posts. But I'm using Reddit less and less as they keep making the experience even worse, especially on mobile, which is more hostile to the Oldreddit interface than ever. After the IPO I expect them to jettison Oldreddit entirely, at which point the site will be beyond useless for anyone who actually wants to use it as a place to read comments rather than as a poor TikTok imitation.
