except AI writing is near 100% detectable. check out something like pangram. no matter what you generate, the cadence of their word choices, sentance structures, etc. are always the same and often blantently visible in the prose. in fact i doubt an LLM of any size now and into the future can properly write without a "fingerprint". real writing, in almost any language, given the possible combination of writing even just a few sentences, even given valid grammar, already exceeds the number of atoms in the universe. because LLMs are transformers, they will always leave behind clues.