I’ve heard (but not confirmed) that’s how some CAPTCHAs work. Clicking the right boxes is a minor metric, what they’re mostly looking for are realistic human mouse movements.
What they're actually looking for is you to click the boxes slowly like an elderly person. Which is frustrating when you have to get through 1000 captchas.
Try to automate anything that requires a CAPTCHA. do the CAPTCHAs manually. You will quickly become fast at clicking boxes. You will notice you always fail the CAPTCHA. Click them more slowly, and you stop failing the as much.
That might be what recaptcha claims, but in reality it's just based on your IP reputation, any google cookies (ie. if you're signed into google), and client fingerprinting.