So with this information, should copyright exist, and if not, how do you encourage artists and scientists to produce works if they no longer can make a living off of it?

I can only speak in my case, but as someone who has been building a career in art and design I’m already looking for another career. It’s unlikely I’ll bother publishing anything I make on my own once I fully make the switch. It’s simply not worth the high risk of investing so much time and energy into a refined skill only to have an individual or a company scrape all your work without even notifying or compensating you and use it to train a replacement for you, using your own hard work to make you obsolete.

It’s very clear from the way the public discussion is going in general on this subject that society is going to have no real issue giving the finger to creatives over the next few decades. It’s essentially society doing that thing that cheapster clients do where they try to commission art way below your rate because “You’re an artist, you like making art so making it for me is like its own reward.”