Why can't they just allow the user to whitelist recaptcha?
I'm willing to go through extensive captcha cycles if that's the cost of retaining some anonymity.
I installed uMatrix a while back to recover some anonymity and it worked at first, my Captcha load spiked significantly which was a great indication that I'd succeeded but it has dropped over time. I guess I'm gradually being fingerprinted again.
Google's captcha tests are my litmus paper test that what I'm doing is effective.
Like for $1 give me a certificate that I can use to say "I'm not a spammer" and I can anonymously buy as many certificates as I want.
And then if a certificate is used by a spammer it becomes invalid. Seems like it's expensive enough to be worth using for existing spammers but let normal people pay a $1 every year or two to not have to deal with captchas.
Certificates would be an even more accurate unique ID over what fingerprinting could provide
(Though I don't know a lot about and would be interested to hear criticisms of it.)