Even before AI more people tried to be an author/musician than could ever hope to gain even financial success. I don’t think less copyright will dissuade them.
> every author borrows
Borrows yes. But that has changed drastically in the last 100 years because of what has become the copyright system.
I’ll be long dead and gone before people can make and publish their own LOTR, or Star Wars, or whatever franchise they grew up with. Disney would be impossible to start given the current regulations, all those tales would be locked up, and we would all be worse for it.