I refer to it occasionally since I toured it once upon a time but General Motors built a new assembly factory near Lansing, Michigan that was the most advanced facility in the world at the time.
It's 320,000 sq. meters and employs about 3,800 people across three shifts, so call it 1,300/shift to make the math easy. That's about 1 employee per 250 sq. meters. Except that the machines and robots that build the modern world are enormous. They take up a huge percentage of the area of the factory.
The work that the humans actually performed was typically in small teams of 4-5 people as they wound cabling through the frame, ensured everything was aligned properly, performed a few welds that their 5-axis welders couldn't efficiently reach, etc. It was fascinating to see where the robotic investment wasn't worth it at the time.