- Encourage credit to be given, when people often otherwise not give credit
Even with copyright, musicians steal parts from each other all the time. Same with other art forms. Taking small parts of other people's art is normal and how art gets created. And there are social consequences even under capitalism to stealing an entire work without credit which are less formal than legal ones, but just as important for artists looking to keep doing art.
- Prevent people from making money from something that is given away for free
... this is not necessarily a bad thing. For example, I would happily buy a copy of Mutual Aid by Kropotkin even if Kropotkin or his descendants don't get compensated because someone put in the work to print the book.
- Prevent people from making fake versions of a book, like what happened to the fifth Harry Potter book
Again, there are social and legal consequences even under capitalism for selling people things under false pretenses.
- Through all of this maintain incentive for artists to make art
I 1000% do not want to consume art created primarily for profit. Profit-driven art is soulless corpo-trash. It takes up air that could be used by serious organic artists. Driving out profit-seeking behavior is strictly positive IMO. I want to drive out profit-seeking behavior everywhere forever, but art is a great place to start.