How does the portrayal of villains differ between DC and Marvel? Are they more complex or purely evil?

Marvel villains often have more sympathetic motivations and complex backstories, blurring the lines between hero and villain. Characters like Magneto and Thanos have understandable, albeit extreme, goals. DC villains, while often iconic, tend to be more purely evil or driven by a desire for chaos and power, with less emphasis on their personal struggles. However, this is a generalization, and both universes have exceptions.