[s1artibartfast]

Positive sum exchange is value creation.

To take an extreme example: Selling a starving person a meal doesn't just extract the price value, but creates it too.

You might argue that there are better or more efficient was of creating that value, but the fact that it is created is inescapable.

If you want to make a utilitarian value argument against it, you need to compare it to a real world alternative subject to scrutiny that is just as harsh, not a perfect world one.