Antagon engages in static pie thinking. If capital makes labor more efficient, then labor can produce more - causing economic growth.
What good does it do a capitalist to produce products if there are not enough buyers to purchase them?
We don't have a capitalist system, btw. We have a cronyist Big Government version, which is due to the infiltration of the socialist/communist principles you apparently favor (given your belief that Labor and Capital are enemies).

Not even close!
In fact, my personal life is a banner for capitalism. I'm some kind of
privately educated,
private enterprise-
owning elitist! My view is enhanced from 'up' here. It does not escape me that some of my customers are government agencies and members of the American socialist state. So goes an increasingly substantial portion of our produce in this country. It certainly doesn't escape me, with April just in our wake, that the government asks considerably more from my gains than the average American.
Isn't the premise of tax commie? Where pure capitalism affords me all the wealth created by my enterprise, which I wholly own, the government, as if it owns 3x% of this enterprise, exacts a share from me every year! Consider this: the hoops one has to jump through to hack away at this liability, are all predicated by private assumption of duties or consumption which the governments in socialist or communist economies would displace.
Your statement that capitalism needs customers, doesn't mean that an isolated capitalism will do anything to create them, other than to reduce prices. I recognize, intimately, that wealth creation, the part that makes the pie not-so-static, is realized from
profit. Profit is pursued through
efficiency. Efficiency in our increasingly industrialized world is affected by
capital means of production,
not labor.
Imagine a motor; while iron and fuel will do the work, it cant sustain function without cooling and electricity. These ancillary roles are played by collectivist policies analogous to our capitalist economy.
Peep your stock market! Do investors 'applaud' hiring and inefficiency or cutbacks and technology? I don't know about 'enemies', boe, capital makes a unit of labor look stunning. Anyone looking to criticize the employment market has to recognize that one stunning worker takes the place of a hand-full of others.
A Model-T, for example, was a simple machine, a top-of-the-line Lincoln Navigator comes together with a smaller team, given what I'm talking about. How is the converse relationship between consumption of labor and of other means of production so obscure to you?