The stark, unmediated difference between a social construct and what isn't, is as I stated:
Humans have been in social groups for 100x longer than "antiquity." We have many, many pieces of archaeological evidence that these concepts are extremely variant in a wide range of societies in history and prehistory. We have societies where they don't believe rape is possible if the woman is married to the rapist, for instance. That was nearly
all societies until very, very recently. Even when the bride in question was a child.
All of antiquity you speak of wouldn't consider marital relations to ever potentially be rape. They could condemn brutality, yes, but it wouldn't be "rape." Today we consider it rape when someone copulates with a 13 year old, and I think that was a good decision as a society. But it isn't a decision most other societies in the span of human history have made, not even close. So I know that it's not just inherent to existence...it's something we decided on, and something people could
take from us with immoral politics and policies.
When you say "I can look at that from my perch 1000 years later and say yes, that was always rape because of some ideas we got later on, even if they didn't consider it rape at the time," yes, you're socially constructing a definition of rape. I don't even see how this is controversial.
Social constructs don't mean the construct is unnatural or bad. Social constructs can (and often do) come from observation of society and deliberate, rational observational responses to real situations.
"It's
just a social construct" is the stupidest idea the left has.
You can say "animals have this and that and the other thing," but ok, then those are things that unify us with the animals. Even so, the things that you would agree differentiate us from the animals are things you would also agree are socially constructed (e.g. currency)!