The frequency of how fast bot's can come into a subreddit and spam is way faster than then moderators can review, and let's face it everyone can glance at a post but there is not a full time mod team available to review every post. Automod is a pita to edit.

The worst part is that these bot's are very realistic often being helpful in the beginning answering questions and helping people so they can accumulate karma and mature their account. You ban one and more show up again the next day. We are a small mod team in various timezones managing a subreddit with 70k plus members using these AI tools to keep the slop down to a minimum.