Nuclear energy is a disruptively cheap and simple way to boil water
For the majority of human history, people used their own muscles to provide almost all of the work required for survival and development. A thin slice of humanity achieved a moderate amount of personal comfort and leisure because they were able, often through an accident of birth, to control a portion of the daily work output of hundreds to thousands of their fellow humans. The only sources of work-in the engineering sense-that were not either human or animal muscle came from capturing falling water or intermittently by capturing the breezes through devices like cloth sails or wind mills.