Why is it that we use voltages and watts more often than amperages? 9v batteries, 12v car battery, 1000W Microwave oven. But amperages not so much, even though its “half” of what makes power, A*V=W. What property of amperes makes it so “unnecessary” to be aware of?
Bonus: how many amps and volts does a typical 1000W microwave use?
Popularity, tradition, laziness :)
The danger of electricity is the first thing about it that you learn as a little child. And later you learn: the more voltage, the more danger. Even such people who never learn anything else about electricity know that all their life. Now the voltage has an unbeatable popularity.
Power sources with a fixed voltage were invented before such ones with a fixed amperage. Therefore the voltage was used as “the” number to tell the size of it. People like to be lazy, they like to have one single number to tell the size of things. Accordingly, for the devices that use electricity the traditon was established to say only the voltage (often it must fit to the fixed voltage of the source) and then be satisfied.