And the commenter is right that failing this, such talk can be dangerous because by a sleight of hand you can substitute - without argument - what is supposedly rational with whatever you simply desire at that moment in time.
I agree with the spirit of the parent poster, but to claim the OP is arguing slavery is okay because of raising standards of living is just as dangerous to this discussion.
Now you might say I’m making a straw man of their argument, but then what are they even arguing then? I can’t figure it out. What does “advancement” mean? They alluded to social sciences having various measure of human happiness is and that a “Progress Studies” department could synthesize these metrics into... what exactly? Policy proposals? A religion? Metrics of human well being assume an underlying framework of morale agreement to begin with.
You simply cannot philosophically convert an objective metric into an “ought” without making a ton of morale assumptions. You cannot prove that your morality and values are better than anyone else’s because you will infinitely regress into definitions if what “good” means.
This commenter's argument was just such an argument.
Do we agree that how you present an argument is important in how the argument is received by others?
I don't follow why an argument with "decent awareness" (whatever that could even mean) or one that is non-novel has different standards to a novel argument or one that has less awareness.
Again, the validity of the argument under discussion doesn't rest on the example that was used to explicate it. The examples are separate from the argument (this isn't always the case).
By pulling to the extreme, you can remove a lot of the smaller and subtler points of the argument, to get pointedly at a core issue.
Unless of course the recipient tries to (re-)introduce irrelevant aspects of the fact that you tried to be pointed...
I doubt anyone is making the argument slavery is okay. At least try to argue in good faith. This is a ridiculous example.