I'm not saying that the expense of manual moderation would excuse doing a poor job of moderating, but the top comment talked about spending "millions" on trying to automate moderation as if manual moderation wouldn't cost as much. They're certainly spending many millions on both manual and automatic moderation as it currently stands.

They've spent tens of millions of dollars just settling with the human moderators for their job-related mental health issues https://www.theverge.com/2020/5/12/21255870/facebook-content... .