It's not entirely zero though. I learned/was reminded of this by 'Capital in the 21st century': Poor people make up society, when they are pushed over a certain line of comfort they will apply pressure to the system to rectify.

In these situations rectification can mean one of several things: Decapitating all who are or seem to be in power or inflating currency until being rich loses its meaning.

Obviously those two solutions are not very attractive to the capitalist market players, so there is an incentive to form structure with the goal of sustaining society. Though history shows capitalist markets are not good (enough) at forming that structure (thus their heads roll).

Value, or market forces, supply and demand are inherent in any system where the numbers of people of more than a few are involved.

The poor don't get priced out and die as you write. A potential market attracts problem solvers, yes, to make a profit (not a dirty word always), and new solutions are found to new problems - that is technology. Sometimes it creates new problems, hopefully less of a problem, and the cycle continues. Look at Cuba for what happens when you are cut off from trade, don't allow individuals to decide what they want to be when they grow up, and don't utilize technology and your natural resources efficiently.

I don't think any system, Capitalism, Socialism, what have you, allow you to meet and greet 7 billion people and get to know them to determine what is best for each individual, so yes, I'll go with market forces, supply and demand unless you have the ability to create something from nothing. These things emerge for the most part, and are not fully intentional constructs.