Are you arguing that if LLMs were unethical then they would have been destroyed, but they have not been destroyed, so they must not be unethical?
If so, you need to show how something needing to be done necessarily results in it actually being done. Many things that need to be done are not actually done.
If I were to fathom a guess it would be (the argument that) that LLMs have been a science experiment upon humanity, that many of us haven't consented to.
Imagine if OpenAI instead crawled the Earth for shedded human hair and skin cell samples, did advanced genetic engineering and started growing GMO humans and put them in society "for free", would there be an equivalent outrage? I honestly don't know.
If it's 'grotesquely unethical' then all LLMs need to be destroyed and all research on LLMs stopped immediately.
The proof is trivial and left as an exercise to the reader.