collapse of the old society

Why do you assume trade has anything to do with capitalism? Most trade through history has been through reciprocal gift-giving with no concept of currency. We've found that people transported materials and goods for hundreds and sometimes thousands of miles, even back in prehistoric times. There were vast trade networks spanning entire continents 10,000 years ago. They worked primarily through reciprocal gift-giving. People just sharing things with each other, often in very ceremonial or ritualized ways.

Trade long precedes writing, cities, agriculture, and any form of government that could reasonably be called a state. So your quip about naming a civilization that didn't practice trade misses the point. It's not that there are civilizations that do not practice trade. Rather, most trade has historically existed without any accompanying "civilization."

The real point is that there are many forms of possible government other than simply capitalism or feudalism. Trade is necessary, but neither of those systems are a prerequisite for trade. Hell, you don't even have to have substantial wealth inequality to allow for trade. Through most of history, societies often maintained their egalitarian nature not through some inevitable force, but simply by the power of will. They lacked inequality because they consciously chose to lack inequality.

Many cultures have traditions to openly mock or denigrate anyone who becomes too successful or powerful. They make every wealthy person into a social pariah. They build up cultural practices that discourage wealth hoarding and encourage redistribution. In some societies, the leader would collect tribute all year, but just to have to give all his worldly possessions away at some grand ceremony each year. In some societies the people with the highest social status are those that give away the most resources. In these societies, having a lot of physical goods actually suggests you're a pauper, as you clearly owe a bunch of favors to other people. The richest man is the man that has done so many favors for everyone around him that he doesn't need to own much. People just give him stuff, repaying a fraction of some old favor from long ago. Some hunter-gatherer societies openly mock anyone that hunts too well, just to keep their egos in check. People have come up with all sorts of ways of having trade and the exchange of resources without having to let society collapse into unrestricted greed and avarice. You can have trade without the absurd wealth inequality found in capitalist and feudal systems.

Hell, most economies haven't operated with currency, numerated debt, or even barter. Econ 101 texts will tell you currency came about because it was otherwise inconvenient to barter things. If I have a surplus of eggs and I need bacon, what are the odds that someone nearby has bacon and needs eggs? Econ 101 teaches that currency was invented to solve this problem.

Yet this isn't how most historical economies actually operated! They mostly operated through gift-giving. I work my land and get a surplus of something. I keep what I need, and then give away the rest to my neighbors. No formal numerical debt is ever recorded. Currency isn't involved. I simply share. My neighbors in turn, when they have a surplus of something, they share with me. What debt does exist is in the form of social expectations. I butcher my cow and give most of the meat away to my neighbors. Later when you butcher that sheep you've been raising, you better do the same. You will be given the surplus of others, and you are socially expected to share your surplus in turn. Anyone who was greedy and refused to share in turn was shunned. And instead of encouraging laziness, people were motivated to give as much as they could. An easy path to higher social status was to produce a huge surplus and give it all away. And ultimately, what is wealth but a means of obtaining social status? This is how the vast majority of human beings that have ever lived have lived their lives. The vast majority of people who have ever walked this Earth never once handled currency in their entire lives.

There are so many ways to organize a human society. And we likely only know a fraction of those that have been tried. And we can find this immense diversity of possible societies just looking in the past. But what marvelous forms could we invent now, with all the vast knowledge and technology we now possess?

Think bigger. Human beings are far more creative and adaptable than you're giving us credit for. We are capable of so much more than just the present economic system and the one that immediately proceeded it.