Also, if these devices use a higher voltage, more space would be required to insulate internal components, or material with a higher dielectric would have to be used which may not be cost effective. It seems that transistors in use at the time had a voltage drop of 0.7V and many useful combinations of transistors required at least 3V. This Quora post has some good explanations. There are more complex reasons why certain devices, such as microcontrollers, all use 3.3V or 5V. Wires and other components have voltage ratings, and going above those ratings may cause the electric field to overcome the dielectric strength of the insulation, leading to a loss of insulation and an electrical short. At higher voltage, certain safety considerations come into play. However, there are often practical limits to how high of a voltage is used. An ampere is the current produced by a force of 1 V. If you double the voltage and keep current the same, you can use the same wire to drive a load twice as big. Voltage is often used as a shorthand term for voltage difference, which is another name for potential difference.Voltage measures the energy that a charge will get if it moves between two points in space. An ampere is the unit for electric current, which is the number of electrons flowing through a circuit.

Wires often have an ampacity rating, which is how much current they are rated to handle. It is often more efficient to use higher voltage and lower current. Going off of your post content rather than the title, I think you are asking why use higher voltage and lower current vs lower voltage and higher current to drive an equal amount of power.

Voltage vsamp