Its purpose "if you run the software you should be able to inspect and modify that software, and to share those modifications with your peers" not explicitly resist copyright. Yes copyright is bad in that it often prevents one from doing that, but it is not the purpose of the GPL to dismantle copyright.

Reducing it to "well you can clone the proprietary software you're forced to use by LLM" is really missing the soul of the GPL.

If not for copyright, you could always do that and copyleft wouldn't be needed.