I want my child to become able to do various things for the future, but I don't know how far to push making them able to do things they can't.

A place every parent puzzles over, with no right dividing line. In common: while there's value in "making them able," there's no need to make everything on par with others—supplementing with tools, adjustments, and support from those around is often more realistic (the idea of reducing difficulties on the environment side). What the family decides: how far to aim for "being able" is your choice, based on the child's burden, motivation, and your values. A guide: "is it needed for the child's life, safety, or options?" "is the child suffering?" "isn't there a way to supplement?" Rather than "able to do everything," using "difficulties decrease and the child lives more easily" as the guide clarifies where to put your effort.