I think the solution is fewer solutions. When I am working well with others, there's nothing much to fuss about. When there are conflicts, it's not ideology or a system that wins the day. I think we two would collaborate just fine without such stuff, for instance. What works in conflict is the willingness to discard systems and ideas. Or, even better, the lack of willfulness to enforce systems and ideas in the first place.
Being conceptually slippery enough to get out of any problem comes naturally to skillful people in their fields. The situation at hand provides all the impetus for theory and practice there is. Conflict thrives off of superfluity: superfluous methods, superfluous justifications, and superfluous issues. Methodology and structure gets in the way of skillfulness.
I know that real human power scales on its own without armies and guns forcing it into a certain shape. People collaborate and collude very easily. People form groups very easily. People associate with people. It's probably the only culturally universal thing people do (well of course; culture only makes sense when there are associating people).
If we want association to work well, groups need to be able to disintegrate as easily as they come together. People need to be slippery, too. Without what makes groups cohere, they disintegrate on their own. When you see violence and hierarchy used to keep groups coherent, it means they've lost the essential power that makes them useful.
People like achieving status. Status is a social signal, and it communicates both ways. Status is not held like a title. Titles wax and wane in the status they confer just like every other human object and activity. When we pretend status can be held, that it can be concentrated and preserved, we get problems. If we let status come and go by its own logic, we'd have no problems with status. A society where status is maintained by a legal system will have hierarchies, and it will certainly have problems.
So ways that our current systems-- not just capitalism, fail:
Labor is not free.
Association is not free.
Status is not free.
Even skillful people who believe in property as an organizing force wish to be locally free in these ways. Skillful people want to work unimpeded by the politics of labor, associating with likeminded people unimpeded by the politics of social groups, praised for the inherent virtue of their actions and unimpeded by the politics of status. They only believe in property because it helps them manage the world that is beyond their control, beyond the means of their skill. They use property to create a bubble in which they can live that is free from its control.
People who believe in property because they enjoy its logic, enjoy the wheeling and dealing, enjoy the frantic rush to get more of it, who feel more worthwhile the more property they have are nervous people, who can never be fulfilled, because property's logic does not lead to fullness, the only conclusion is 'not enough', the only purpose is 'more'.
I don't know how many people in the latter category actually exist. I suspect enough to cause a great deal of problems. In any case they require the assent of everyone else. I think all I have to say to everyone else is this:
The world without property is still full and whole, is still just, is still full of vitality, is still nourishing, and receptive to human power.