If the economy only made one product the workers it employs would not be able to purchase the product they make under a pure capitalist system. A more diverse capitalist economy will generate varying strata of workers, but those will be separated at the extremes by their ability to afford the production of those under them. None but the owner class will ever be able to afford the most expensive products.
We get closer to discovering that every time we think capitalism/markets can solve all our issues and cut back federal spending (dollar creation) into the economy, increasing the inequity of money distribution. That inequity is currently higher than it was in 1929 just prior to the great depression.
In fact, the only seven times we have been successful in making headway in paying down our national debt resulted in almost immediate recession/depression. The point I am making here is that "money" isn't a product of capitalism and profit. It is, in the context of modern economies, produced and managed by governments as a means of deploying real resources and labor into the private sector where they can be purchased with the unit of measure the governments create at will.
That money can then circulate among owners and workers of production with governments serving as price setters for the goods and services they use. Production and purchasing of products and services cannot be "net" funded by private sector debt, as the debt would never be retired without injection of public money. Neither would profits be available to "net" save as a store of value/wealth. The "debt" (total public money created - that destroyed by taxation/gvt revenue) becomes our net money supply in the private sector, which is why the private sector can never be responsible for that debt. The government's red ink is our only net source of black ink.
Governments should use their power of money creation in securing value/wealth for the people in ways most would describe as "socialism", such as modern infrastructure, education, health care, retirement security, job assurance and other things that are burdens shared by all and that markets cannot effectively deliver and build into their overhead. Only the currency-issuing government can do so without inflating the end cost of production, and those things are always the first to go when private sector production needs to compete with others for market share.
The one thing governments do really well is paying for things, at least if they are creating sovereign fiat currencies and accept debt only denominated in the currency they create at will. Democratic governments are best suited to distributing/allocating that currency in the best interest of the society if they are not subverted in that by fraud or corruption, which is a great incentive for public funding of campaigns.
Cost efficiency is not really a factor in this, and shouldn't be a goal to shoot for as it is in the private sector. Effectively carrying out its mandate to provide "for the common welfare" and to create its currency to do so means that government's sectoral balance will aways be in deficit, which is beneficial once one "gets" the red ink/black ink concept of budgeting. However, the currency creating government will be largely responsible for resource deployment/allocation and should be mindful of the private sector's use of resources and labor to avoid monetary inflation by not competing with the private sector for those.
It can "afford" anything that can be purchased that is potentially available and denominated in its currency, but that doesn't mean it should disregard cost completely where such potential for competition exists. Congress could "afford" to pave the entire country, end to end, but it cannot produce the required materials of concrete, steel, machinery, or labor necessary and would put all private sector use of those out of the running if it tried.
Government should always use its currency-creation powers in countercyclical support of the business cycle. The best way it can do this is with a federally funded (but locally managed) job guarantee to replace the minimum wage and the use of bond interest as inflation prevention. (Inflation of a sovereign fiat currency is always a matter of supply problems, not monetary problems or spending) This sets the bottom for wages and benefits in the private sector, so it should be considerably better than the minimum currently in both.
It also injects new money creation exactly where and when it is needed to shore up supply chains and prevent areas stricken by layoffs from deteriorating as we have seen in many former manufacturing centers. Many of those areas would find such a labor pool, not to mention the money added to their local economies, very welcome and would have little trouble finding constructive us of both.
