I read this sci-fi short story in an anthology book in the early 90s.
The story was about a dystopian future where all the natural resources had been used up and people were struggling to survive. Early in the story, a small, automated cart delivers a small amount of food and supplies to a group, but it isn't near enough for them, but the cart asks for requests for the next delivery. The main character attempts to give a command to make it stop delivering, but the device doesn't understand and states that it would return with the standard delivery.
From there, it is explained that the automated delivery cart was part of an old automated system set up generations before by a society that had grown technologically advanced enough to create machines to take care of gathering natural resources, processing them into usable materials, and then automatically distributing them to all people everywhere. The technology was so advanced, that it was capable of creating new processing factories to process all resources that was automatically gathered. The problem came when the machines were so efficient at gathering natural resources and processing them that it eventually stripped everything useful and had automatically modified all power and other resources that the society need to survive to keep up with its programming to keep gathering resources to process into goods to distribute.
In the last part of the story, the man who had been trying to figure out how to command the machines to stop what they were doing, managed to stow away in the cart and ride it back to the factory where he hoped to shut it down at the source. Rather than being a large factory, he discovered that the machines were in the process of 'scaling themselves down' to smaller sizes. Indeed, the deliveries used to come in a larger truck, but the change to a small cart for deliveries was part of the machine's strategy at 'conserving' the resources left.
To the man's horror, he discovers that the factory had retooled itself and was making tiny versions of the gathering units, the processing factories, and the distribution carts that were all in a tiny box the size of dice. He watched as one of the delivery carts sets back out into the environment and distributes the tiny little dice sized boxes all over the place like fungus spreading spores.
The machines' final strategy was to keep creating smaller and smaller versions of itself until every atom of natural resources would be gathered, processed, and redistributed as tiny, microscopic deliveries to humans who would no longer even be able to see them with the naked eye.
So, has anyone else ever read that story? Any ideas on author or name? Thanks for reading!