The short answer is "most work through history has been outside the market", and that has changed massively in the West only in the very recent past. In almost any historical context, most work was directly toward subsistence, and only a very few people worked for money. Even those who did work for money still had subsistence work as well - kitchen gardens and a wide variety of domestic chores, for example. Much of my area is food and agricultural history, and paying for that is a very late development.

Feudalism is an illusion, and hierarchical feudalism doubly so. But the fact does remain that the vast majority of the population in Medieval Europe were peasants. They rarely travelled far from their homes - most never travelled far from their place of birth - and they worked the land for other people, lived in buildings owned by other people (usually the same other people), and quite often didn't have any day to day use for coin. Even the tithe owed to the Church was often paid in goods, rather than money. There weren't shops from which they could buy things, particularly, and informal barter-like arrangements were probably more the rule than the exception.

Even when coinage and other forms of monetary exchange came into wider use, there was still a lot of unpaid labour going on. Family members were expected to contribute in some way, whether it was cooking, cleaning, taking care of children, or actual participation in the family business, whatever that happened to be. The family business might sell things, but the internal transactions, as it were, were almost always unpaid. And a lot of things we pay for - hair-cutting, clothes-making, food preparation, for example - were done at home by relatives.

This remained true for a lot of people up to the mid-20th century. Our lack of kitchen gardens in the modern West, for instance, is a historical anomaly.

The fact that much of this work was done by women and by people who were at the less literate end of the scale means that there's not as much record of it as might otherwise exist.

For useful books, try The Historical Meanings of Work, by Patrick Joyce - while I've had cause to reference it a couple of times, I haven't read it in its entirety, but it might go some way toward addressing some of your questions.

Sources:

Georges Duby, Rural Economy and Country Life in the Medieval West

Steven Epstein, An Economic and Social History of Later Medieval Europe, 1000-1500

Vera K Niñez, Household Gardens: Theoretical Considerations on an Old Survival Strategy