First time I pressed a button to start an automobile, I felt like I'd strayed into a tax bracket I don't belong in.
The push-button ignition doesn't bring any additional capabilities (in this case, the ignition system that has you insert and turn a key).
It exists for convenience, which it does well. In the automobile, you push the brake pedal and a button to start driving.
Pushing a button to start a vehicle lets you transport yourself, your family, baggage, and hundreds of pounds at highway speeds.
The buttons themselves are common throughout the vehicle industry, which is surprising given how diverse keys may be.
Every one I've seen is spherical, to the right of the steering wheel, and has on-car lighting.