The main thing that bothered me, and I don't see anyone talking about it though.
If the Amazons of Themyscira have acknowledged Circe's visions as real, and will trust their lives according to her visions. Why didn't they help Circe with their army? Seems like a plot hole that they acknowledge Circe is a real prophet, then they abandon her and the decide to let the world be destroyed for unknown reasons. So that Circe has to go get the convienent sons of themyscira to help her instead of the highly trained amazonian army.
It really feels like Gunn didn't care about continuity and wrote it to be "Circe needs justification for her visions because i wrote her into a corner and she needs to be justified for this story to move on" without thinking about what would follow with that line of reasoning.