Is there actually a widespread benefit to forcibly upholding the gender roles?

it's complicated but given that they're a near-universal phenomenon (despite what those roles are not being universal), i do think it logically follows that humans collectively derive some social value from their continuation―although i think opinions would vary heavily on what that social value is. in any case it doesn't seem likely we'd spontaneously invent and almost universally adopt a social construct with no intrinsic benefits.