If we abolish copyright then there is no need for GPL. I am so forever grateful for GPL, as Stallman and the like weaponized copyright against itself, and then gave us crystal clear data that open source software is strictly superior in the long run.

But even if only 1% of ideas were copyrighted, that is still a tax on the use of all ideas. In a world without copyright, I can download any dataset at will and analyze and remix it to my heart's content, and share my findings. But in a world with copyright, if there was one "copyrighted" land mine in there I open myself up to financial ruin. So one must tread carefully when working with any external ideas.