Modern industrial economies are really complicated. I like trains. To make trains, you need parts, labour, equipment and power. They themselves need to be made, which uses parts, labour, equipment and power, and meanwhile you have competing uses of all those things for making, I dunno, printing presses, or for completely different things like farming or art curating. If you drew it all out as a diagram it would get super interconnected super fast.

Meanwhile, even a simple binary choice like which of two lots a rehab center should go on can be very politically complicated. Anarchists like to handwave it away with "we'll figure it out together", and I really don't find that convincing.

Markets offer a system that's proven to work insofar as if you need to buy a train or a hair clip or lunch someone's always selling it. How do you guarantee that, or something similar?