It doesn't detect "real browsers". It simply adds some friction and is niche enough that AI scrapers have not bothered to bypass it yet.
There is enough visceral hatred for the Anubis branding, I am surprised an AI skill for bypassing it hasn't been broadcast yet.
Most of the friction is just JS overhead for the computations, a compiled solver is like 1000x faster. If Anubis ever gets popular enough that scrapers care, it would be trivial to defeat. And last I checked you could bypass it by just modifying the user agent
Yeah this is one of those things that hurts some real users and AI scrapers have figured out how to bypass. Not worth it IMO.