Most vision-impaired users have no issue in our testing, and it is a much more accessible option than audio challenges, which discriminate against those with auditory processing impairments.
(disclosure: work there.)
> If you are using the very latest version of Safari on either the recently released OS X 10.15 or iOS 13.4, Apple has just changed the behavior of Safari related to third-party cookies, blocking all of them by default. We are implementing a solution, but in the meantime please visit Safari Preferences, Privacy section, and uncheck "Website tracking: Prevent cross-site tracking" to enable the accessibility cookie to function as expected. [0]
[0]: https://www.hcaptcha.com/accessibility
So while you're patting yourself on the back for not "being like Google", your accessibility workaround exposes blind users to third party trackers like Google.
That said, we're working with the browser makers on native support for our next gen privacy-preserving approach to this via Privacy Pass.
Holy moley! Yeah, that's a deal-breaker. I agree that this is entirely unacceptable.