I can't speak to every local subreddit but I can tell you for sure that while it may have started as an anti-bot measure, on /r/newzealand it is absolutely used

I can't speak to every local subreddit but I can tell you for sure that while it may have started as an anti-bot measure, on /r/newzealand it is absolutely used as a way to gatekeep the wrong opinions from being present on the subreddit.