Why is the BMW iVision's electric engine more efficient than a traditional gas engine?

I've heard that electric engines are more efficient, but I don't understand why. Can someone explain the specific differences that make the BMW iVision's electric engine more efficient in comparison to a traditional gas engine?

Electric engines have fewer moving parts compared to traditional gas engines, meaning there is less friction and wear, resulting in a longer lifespan. Additionally, electric engines convert almost all of the energy they receive into forward motion, while gas engines waste a significant portion of their fuel through heat and other processes. This makes electric engines more energy-efficient and ultimately saves money on fuel costs.