And even if they’re not being held at gunpoint, a difference in available information between the parties can make it unethical. Consoder if the employer says someone’s labor is worth x amount, but it’s really worth significantly more. But then the employer doesn’t disclose that and does everything in their power to make sure the employee doesn’t know the true value than their labor, that’s effectively lying and therefore unethical.

Willing agreements can only be ethical when all parties involved are fully informed. It’s one of the fundamental principles under age of consent laws