Duplication is only one half of the economic picture. You don't need to explain to me how the costs of duplication have fallen to zero, but I would like you to address the fact that the fixed costs of creating something people want to duplicate are very far from zero.

Humans have been creating art, with or without economic recompense, for thousands of years, they're not going to stop now.

And for the longest time art was the preserve of the wealthiest segment of society that used it as means of keeping the population in line. The idea that people who work in the arts should not be allowed to use technology to monetize the product of their labor is a bunch of self-serving bullshit. Nobody is entitled to have an artwork they produce become successful, but if it does become successful (in terms of people wanting to watch/listen/read) then they're entitled to something in return for the utility their product has provided to the consumer.