The earlier three-person economy conceals a situation that emerged in the distant past as we developed beyond the subsistence level. The raw materials needed for hunting and gathering, and also in the three-person economy, were already in existence and freely available for the taking. It was what is known as an empty world - a world where the ecosystem was vast and raw materials were plentiful compared to the demands made by humans. As the human population and its demands increased, the areas of accessible and fertile land that were unclaimed diminished, so a person who was not already a landowner could not grow food without the agreement of and usually payment to the landowner. At this stage very few people had the ability on their own to create wealth, either for their own subsistence or as a surplus to trade with others.
To create wealth in the modern world people need access to productive capital, at least in the form of land and seed, or tools and raw materials, together with necessary skills. These are no longer available for the taking, they are normally only available through employment. This is why employment is so important. The problem is that the owners of productive capital won't employ others unless their own interests are served in doing so.
Without external constraints this situation creates a very unequal partnership. Throughout history before there were employment laws the owners of productive capital had much greater bargaining power than those without, and used that power to enrich themselves by appropriating the bulk of surplus wealth created by their workers.[64] This is what makes the distinction between needs and wants and their relative possession so important in terms of bargaining power. All classical economics saw was a willing buyer of labour and a willing seller. It had no interest in the reasons for the willingness of each - the buyer's because he or she gained all the surplus wealth and the seller's because his or her life depended on it. With no constraints employers held the very lives of their workers in their hands and could take for themselves everything their workers produced beyond their survival needs.
Thankfully things have improved very considerably in this respect in modern times, especially in the developed world, but the relationship is still unequal, and there remains the basic irony that a person has within him or herself the capacity to create wealth but is unable to access that capacity without the assistance of another person.
Each person has within them a wealth-creating engine, but the ability to start the engine lies with another person, who won't start it unless it is in their own interests to do so.
There is a further requirement, which is that in order to trade wealth one or more other people are needed to trade with. Hence the product must have value to others, and the more valuable the more successful the producer - at least until competitors enter the market. For employed people the value of the product is the responsibility of the employer, whereas for the self-employed it is the person's own responsibility.