Why use a sand blaster when you could polish something by hitting it with one huge rock? Why have thousands of individual car fuelling stations when everyone c

Why use a sand blaster when you could polish something by hitting it with one huge rock? Why have thousands of individual car fuelling stations when everyone could drive to one giant one in the middle of the country? Why have a steam turbine in your nuclear plant with many small blades? If your thousand spoons work pretty much untended and cost half a million each, then an excavator that requires a crew of a thousand which costs ten billion is just as stupid as all of the above.