In the early years, electrics had a very significant advantage over gasoline and stem-powered cars - they were easy to start. All you had to do was flip a switch, and, assuming the batteries were charged, the car was ready to go.
With a steam car, you had to stoke up the boiler and wait for the better part of an hour before you could get going. Not exactly convenient. Add to that the possibility of the boiler exploding if you weren't an expert, and it was pretty clear that this method of combustion was not going to be long-lived in automobiles.
Gasoline cars were easier and more convenient to start than that, but you still had to get your spark and throttle controls set just right and then crank the engine started. For all but the most adventurous women of the day, it was unthinkable to engage in such unladylike behavior. For men, it was all part of the adventure of the automobile, but it was still a pain - sometimes literally. People were injured, maimed, and even killed by the crank spinning back on them. In fact, this is what inspired the invention of the first reliable self-starter for a gasoline automobile.
Byron Carter, the founder of the Carter-Car Company, stopped to help a woman whose car had stalled. He didn't check the spark before he tried to start it. The engine backfired, and the crank spun back, breaking his arm and smashing his face and jaw. He died of gangrene a few weeks later.
His friend, Henry Leland, at the time the owner of Cadillac, vowed to develop a self-starter for a gasoline automobile that really worked. Self-starters had been around for a while - they just didn't work well or often. So Leland brought in Charles Kettering, the inventor of the electric cash register and an electricity generator known as the "Delco" (a sign of things to come for Kettering). Kettering introduced his self-starter in early 1911, It was first used in the 1912 Cadillacs to great reviews, and went on to sweep the industry.
The advantage in easy starting that the electric had over the "infernal combustion" vehicle was gone, and with it a significant percentage of the electric business.