This has been an expansion of no man's land by 100 times since world war 1. US military planners are talking about massive layers of combat. They are basically saying that the first layers tens of miles deep needs to be expendable and they want it to become all drones and robots.

Historical Expansion of Deadly Zones

There has been a historical trend of expanding deadly zones in warfare:

World War I: "No man's land" between trenches was indeed roughly 100 yards wide. Sources confirm this was a zone of extreme danger and death.

World War II: The deadly area expanded significantly to approximately 500 yards. This increase was due to more mobile warfare, the use of tanks, and more effective artillery.
It has gotten even larger in the Ukraine-Russia war with ten thousand or so drones per day used. Deaths and wounded on both sides is about 1000 per day.

Militaries are in the process of transition to highly deadly depths of 6-9 miles (10-15 kilometers).
US Military Planners are looking at layers of combat hundreds of miles deep and the front layer or two need to be unmanned in most situations because they will be too deadly.