Are you religious? If not, you should assume that your cognition is a product of your body, a magnificent machine.
I don't think LLMs are sapient, but your argument implies that creativity is something unique to humans and therefore no machine can ever have it. If the human body IS a machine, this is a contradiction.
Now, there's a very reasonable argument to be made concerning the purpose of copyright law, but "machines can't be creative" isn't it.
Creativity is not unique to humans, but legal rights to protect creativity is unique to humans (or human-represented organizations). Humans are always special case in law.
Selling human livers and selling cow livers are never treated the same in terms of legality. Even the difference between your liver and that of a cow is much, much smaller than the difference between your brain and Stable Diffusion. I'm sure there isn't single biochemical reaction that is unique to humans.
Converting a raw 8k video down to 1080p is a full of creative solutions and its perfectly fine to see it as the machine doing some form of creativity when optimizing performance and file size. In similar way, compilers are marvelous and in many cases ingeniously when building and compiling binaries from source code.
It is however general agreed on those do not create independent original works. At the most generous interpretation they get defined as derivatives, and at the more common interpretation they are plain copies. The creativity is also usually not given to the machine, but those who built the machine. Even if the programmer is unable to predict all outcomes of creative written code, a unpredictable outcome is still attributed to the programmer.
It was ruled that our Copyright Law does require that a Human create the work, and that only a Human can hold copyright. The monkey was not given copyright over the image it took.
Monkeys obviously can be creative. However, our law has decided that human creativity is protected by copyright, and human creativity is special within the law. I don't see any contradictions or arguments about sapience that are relevant here.
I don't think LLMs are sapient, but your argument implies that creativity is something unique to humans and therefore no machine can ever have it. If the human body IS a machine, this is a contradiction.
Now, there's a very reasonable argument to be made concerning the purpose of copyright law, but "machines can't be creative" isn't it.