You could not go an buy a light bulb to put it somewhere where you wanted light. That doesn't mean it didn't exist. It was just not available and the ones that

You could not go an buy a light bulb to put it somewhere where you wanted light. That doesn't mean it didn't exist. It was just not available and the ones that existed probably didn't serve well as a light source. Smartphones however where in stores you could buy them long before Apple made one and they had all the functionality of apples first smartphone.