That is because I do not think Google's aims for captcha are the same as ours.

I can tell you that as soon as you download Chrome and login to any Google account of yours, the captcha tests are suddenly and mysteriously gone.

Use firefox in full-lockdown mode, and you will be clicking fire hydrants and crosswalks for the next several hours.

My crazy conspiracy theory is that Google is just using captcha as an opportunity to force everyone out of privacy mode, further empowering the surveillance capitalism engines. The intent is not to be effective, but inconvenient.