Everyone has a smartphone is close enough to the truth. There are people living in mud huts that have smart phones, even though they cook on an open fire and use candles for light. More than half the world population has smart phones, and even some very poor countries have surprisingly high penetration.
World population is in the 8 billion range last I checked, while smart phone owners are over 5 billion. That is most, and close enough to everyone for discussion.
