You're quite right about the books I remember the Self-Help series for all kinds of legal documents, but they were essentially dumb. If the person using those forms made an error it probably wouldn't be caught and could be costly. Modern electronic systems have, what may be described as intelligence, though certainly not understanding, such that user error should be much less common. Also with consumer grade financial software different scenarios can be evaluated and actions suggested based on data analysis; so there's more than just UX improvements occurring in these systems.