There are things you can do to verify humanity.
Make a human go to a place for example (though even this has difficulties with fraud). I'm not making any specific claims about world coin other than the goal they're trying to solve makes sense as a goal in a world where bots are increasingly capable of mimicking humans successfully, we want to know when something is human and when it isn't.
Attempting to solve that problem now before it becomes critical makes sense, not every attempt will be good.
A better article than this one would have dug into that problem.