Reviewers saying that this add-on doesn't work most probably do not understand how it is supposed to work. They think this is a magical add-on that just removes any need to solve a captcha, but that's not the case.
This add-on allows you to solve a captcha first to fill up 30 passes (for each captcha), then use these passes when you encounter captchas as you surf.
This add-on does not work on Google's captchas, it is designed for hCaptcha only, which is not very wide spread, but Cloudflare uses it natively, and Cloudflare IS widely-spread..