I've wondered for a while if simple interaction systems would be good enough to fend these things off without building up walls like logins. Things like Anubis do system checks, but I'm wondering if it would be even easier to do something like the oldschool Captchas where you just have a single interactive element that requires user input to redirect to another page. Like you hit a landing page and drag a slider or click and hold to go to the page proper, things that aren't as annoying as modern Captchas and are like a fun little interactive way to enter.

As I'm writing this I'm reminded of Flash based homepages. And it really makes it apparent that Flash would be perfect for impeding these LLM crawlers.