"If it is not advantageous, i.e. prosperity increasing to build a road, then guess what? It won't be built"
Right, lots of necessary goods which have a prohibitive private cost will just not be built. The market is a piss poor coordinating mechanism because it relies on exchange. Massive forcible reallocation of resources is very often necessary for economic growth. For example, the Meiji Restoration would not have been possible without state-led land reform.
Funny listening to libertarians talk about 'societal values', since they think 'community' itself is a socialist concept and a myth. There are no values in your libertopia, societal values require a society which is another socialist concept. You're a bunch of greedy individuals who can't coordinate difficult tasks because of the prohibitive cost.
The individual is nothing without the community. From birth, you are stamped with the imprint of your community. You cannot even think without language. Where do you think language comes from? Individuals? Language doesn't exist in a vacuum.
I'm wondering though, which "values" markets preserve. Maybe the 'value' of stealing from pensioners, taking out life insurance policies on old employees and pocketing the benefits. Maybe it's the value of exploitation/reality tv, in which vulnerable people get attacked, insulted, and degraded for people's entertainment. Maybe's the value of turning human beings in human chattel. Great values, all of those.