What I mean by “confusing” is that it’s harder to estimate. A joule is a newton multiplied by a meter, which is essentially the work you do when you lift an apple (which experiences around 1 newton of gravity) from the ground to a table (which is around 1 meter). So using megajoules should be more intuitive compared to kilowatt-hours. What makes kilowatt-hour easier to the layman to understand is that electric companies charge by kilowatt-hours instead of megajoules.