Governments have always been around to keep social order. In theory they can accomplish things that individuals and private collectives can’t afford or don’t have an interest in. Plato said that the commons is neglected by the polis and is the worst kept area in comparison to private interests. Private interests though have their own interests in mind and not those of the public. A libertarian society, if such could actually exist except in a frontier setting with corruption being the rule rather than the exception and a Frank Reed like character needed to free the town of its Soapy Smiths, would likely be a rathole.
In a libertarian society infrastructure would grow incidentally without regard to public interest. If the technological tool kit required for building infrastructure is simple and if the demands on society are simple the infrastructure may self-regulate. Consider a primitive society with people hunting seals on the ice with spears- they require no public spending because the society is simple and services are provided by nature. Compare that to England in the industrial revolution when people were getting cholera of drinking water from the Thames river- the remedy required public mediation to treat all that sewage effluence.
The nation today has people going off in a zillion directions chasing after tangential political ideas that will not allow the national or global economy to continue to exist very far down the road with more than 12 billion people on Earth by the end of the century. Excellent new ideas need to appear that can coordinate planetary redevelopment toward a new direction of ecological economic synthesis and libertarian won’t do that. Neither will communism or socialism- each have problems in repressing free enterprise where new structures need arise from invention.
Americans in the private sector are quite concerned with getting their special economic interest gored when new and massive government-directed changes take places that would allow an infrastructure of sustainable support for 12 billion people. Governments don’t have a surfeit of inventive people able to originate and explain great redevelopment ideas obviously. Jacques Cousteau and James Lovelock each expressed the idea that humanity has fewer than 200 years left before collapse and I tend to agree with that prospect. On basic political facts and forms they are confused and splintered chasing after things that won’t work very far into the future.
Public and private interests each can mismanage infrastructure and keep existing forms long beyond their historical time for utility. In the present global environment that is akin to packing gunpowder for storage in a warehouse on the waterfront as occurred in Lebanon last year.