Yes, there is a complexity limit, but it is fuzzy and not perfectly well defined (and that's ok). Modern LLMs ride that line in a wild and interesting way.

It's really fun having become a biologist in recent years, and knowing that there's an entire field that uses living organisms (yeast or neutered E coli) as protein factories. I am bringing it up a bunch here because not only are these things used as tools, but they're literally alive!