@james I tried just yesterday to register an account on a site that uses HCaptcha. I use a screen reader on Windows and Firefox as my browser. It was completely unusable. It asked me for an 'accessibility cookie' that requires to give them a 'real email' address, refusing to accept my Firefox Relay alias. After caving in and giving them an address that i had given them a few years back and getting my accessibility cookie, the bloody captcha refused to recognise the cookie. Checking their support pages and tinkering with Firefox settings, none of which worked, I gave up and had to wait for a housemate to arrive after her work to help me solve the captcha.
BeAware