That's because Chrome tracks so much telemetry about you that Google is satisfied with how well it has you surveilled. If you install a ton of privacy extensions like Privacy Badger, uBlock, VPN extensions with information leakage protections, etc., watch that "accuracy" plummet again as it makes you click 20 traffic signals to pass one check.
I stop going to sites using that method due to this. I have no intention of proving I'm a human it I have to click several dubious images 3-4 times in a row.
