No, the Bible is not a book of Greek Mythology. It's rather a book that originates from solid ancient Jewish writings. The bible's Hades is just the biblical Greek for Sheol.

Proof? The popular Greek version of the Hebrew OT uses Hades for Sheol. (This Greek OT is used extensively by the NT writers while quoting the Old Testament. So its reliability is solid). The Bible's Hades is simply Sheol/Grave.