Why would world war 1 be described as the first major war of the industrial revolution?

Out of all of the wars in the Industrial Revolution, more than 70 million personnel, including 60 million Europeans, were mobilized in this large war and more than 15 million people were killed.

In all of the wars in the Industrial Revolution, more than 70 million personnel, including 60 million Europeans, were mobilized in this large war and more than 15 million people were killed.