Copyright law has existed for only a few centuries, and people created art and science before it, as careers, for the entirety of human history. These jobs would be a lot different without IP law. They might be payed less and be done less, or maybe not. If they are payed less, it's true probably they wouldn't be as prolific. But they would still exist, it's disingenuous to claim IP law is a requirement for creative endeavors.

As a matter of fact, programming already works as if IP law didn't exist from the point of view of many programmers.I'm hired by a company to produce a product, in exchange for a salary. I don't know any IP that I might produce as a result of my work. I'm simply paid for my time. Could (as an example) novel writers be payed for the time spent writing a book rather than as a function of the sales of their books? I see not logistical reason why not. Maybe the market won't bear many writers under those conditions... But they would still exist, right?

Note: I think Trademark law is really good. And patents have issues but they are mostly good. I'm only talking about copyright here. I'm not entirely against the concept of IP, but I do think copyright law is not nearly as critical as it's made out to be. Maybe the optimal solution is weak copyright rather than no copyright, but I think it's important to understand that no copyright is not as crazy as it sounds.