People keep saying open source is an example of how copyright doesn't quite matter. However, many of the biggest open source projects are contributed to by massive corporations. Linux has lots of contributions from all the FAANGs, Red Hat, etc. Yes, it's not protected by copyrighted, but also the way it's produced is wholly different from how an artistic work is produced. Contributing to Linux is nothing on the balance sheet of Google for example, whereas producing art for an independent person or a whole company who's purpose is to create art can be very expensive.

Artists are taking risks and need legal protection if they want to make art for a living. If artists were making FAANG engineer compensations or all worked at institutions like universities (with all their protections) then maybe they wouldn't care about copyright, but that isn't the living situation for every artist.

You could say an artist shouldn't rely on making art for a living, but that's actually a different discussion.