That's why the free market works, millions of agents in parallel beats any planned economy (by humans)
As a small wrinkle: the actual observed number of producers can be small, but the market still be competitive. See https://en.wikipedia.org/wiki/Contestable_market for one case: when potential suppliers are waiting on the sidelines.
The exact same thing happens in the cortex, 10s of thousands of cortical columns coalesce into a single action.