Undermine the usefulness of llms in an attempt to force people to visit your site directly.

If one doesn’t want LLMs to scrape data and knows the LLMs will be ignoring the robots.txt file.

Keep in mind you're asking this question on a site where users regularly defend the Luddites, Ted Kaczynski, and other people who thought they were doing great things for humanity but who actually weren't even doing themselves any favors.