Google captcha works by uniquely identifying you. The easier Google can track you the easier your captcha. That's why it's nearly impossible to solve captcha with resistfingerprint on (ie tor mode)
Ideally I’d like to see fewer captchas. But there’s no good alternative to it really. I mean, requiring phone verification instead is an alternative. But I don’t necessarily want to hand out my phone number to each and every site on the net that I interact with either.
How do they decide which captcha is harder ?
I think that only two things can defeat this madness
1. Legislation
2. Breaking captcha to the point it's not effective anymore