What are the most challenging objections to the divine inspiration of the Bible?

What are the most challenging objections to the divine inspiration of the Bible? Are there particularly compelling arguments that skeptics of the divine inspiration of Scripture commonly bring up to justify their skepticism? *Note: this is the counterpart question to [What are the strongest arguments for the belief that the Bible was supernaturally inspired by God?](https://christianity.stackexchange.com/questions/83868/what-are-the-strongest-arguments-for-the-belief-that-the-bible-was-supernaturall)*