Take a world globe. It has a spherical surface, impossible to see all at once. Its features are hard to visualize when turned away from our view. Its locations are measured by a framework of 360 degrees around its axis, by 180 degrees from pole to pole. Its land and ocean masses appear randomly scattered by Mother Nature - which is precisely the case.
Most globes are hard to handle, and impossible to fit in a book bag.
Look at any wall map of the world. Our national geography standards recognize that no single map can accurately depict all Earth's properties. Now refer to an elementary geography text. Each chapter is illustrated by gorgeous flat maps. With few exceptions, these separate 2-D maps will have been produced at different scales and by a variety of projection methods.