The point is that we don't need an equivalent number of nodes (agents) as we needed people.

The computer flattened the coordination dependencies of that room full of people by doing all the calculations by itself. As they get smarter, you can theoretically assume 1 agent could eventually run the entire US federal government.

In the historical [human] computer example; if 15,000 calculations needed to be done, a CPU doesn't need to wait on Bob to come back from lunch to do the next 20 calculations...and doesn't need to wait on Alice to combine his work with the 20 calculations done by Jane...and doesn't need Bill to wait for everybody to be done to double check Jane's work.

The CPU does all 15,000 calculations instantly, by itself. This will be similar with AI agents.