The Villains Are Sympathetic

While it's too early to say whether there's any sympathy to be had for the demons chowing down on human children, the humans in charge of raising them have surprisingly understandable motivations for doing so.

This next part contains spoilers, so if you want to enter The Promised Neverland without any foreknowledge, keep scrolling.

Isabella and Krone are adult women whose job is to raise children in a safe and joyful environment until they're due to be shipped out for slaughter. Why, you might ask, would any human being sell out their own species in such a grisly way? The answer is simple: self preservation. They were born into the system, destined to be eaten themselves unless they took this terrifying job offer. While playing into a corrupt system in order to save ones' own neck isn't exactly heroic, it is deeply human - and it makes it hard to fully hate either of them.