I don't think that people with disabilities or "special abilities" as some call them do less than other people do.
To be more precise, i am sure that the World would not be the same if only the "non-disabled" existed.
Looking around I see many people not doing more than the 1/10 of what they could.
For several reasons and mostly because they want to live well without doing a lot.
In the contrary, people with disabilities do much more effort to complete tasks in life, whenever it is possible. They need to prove themselves they can do things, and others to see them as equal.
That means that disabled people do more, because they have to fight against disability too.
That means that all of us need everybody else, disabled or not.