I don't think the defining feature of capitalism is lack of bartering or the use of money. It's the "private ownership of the means of production". It involves the extraction of a profit (the owner ends with more stuff than he started with) based on the fact that he can marshall the means of production (labour, materials) at a lower cost per unit than price he charges per unit, thus obtaining a profit margin. Ten individuals acting on their own with ten units of wealth each (dollars, apples, biscuits) will not be able to achieve what one individual with 100 units of wealth can achieve.
Whether exchanges take place with money or apples and biscuits is irrelevant. If I end up with more apples and biscuits than I started with and I didn't do any actual work but merely recruited the means of production with fewer apples and biscuits than I got in exchange for the finished product, that makes me a capitalist.
Money is more convenient than apples and biscuits, it enables the unhindered operation of a free market in the case that people go off apples and biscuits, or in the case that the apples and biscuits themselves go off.
This is why 1% of the people have 99% (or whatever) of the wealth. The rich get richer because they can leverage their wealth. That's capitalism, and the inherent unfairness in the system is the reason for socialism, i.e. taxation and redistribution. The alternative to taxation and redistribution is revolt and murder - which is why the rich agree to it! They don't want guillotined.