@JonnyT I am not saying it is THE solution, but if you want safer open registration, then it is _a option_ to help with that. It's something that exists today that makes open registration that bit safer.
If you're running closed sign-ups or approval based sign-ups, you don't need hCAPTCHA.
Like, I'm not posting about this to argue about it. Feel free to do a pull request to the documentation if you think it can be improved.