I assume the income inequality here is owner vs worker, rather than above average worker vs below average worker. I expect the gap between workers in most field

I assume the income inequality here is owner vs worker, rather than above average worker vs below average worker. I expect the gap between workers in most fields is much smaller than the gap between the owner's profits and the salaries of each worker. The idea is that, in a traditional company, the owner (or stockholders) puts up all the investment and risk and in return, get the lion's share of the payoff. In the coop, there is no 'owner' and any profits that aren't reinvested in the company are divvied up by the workers. The trade-off is the difficulty in finding investment capital to get started, which is why many coops are simple businesses like cleaning services that can be started by workers pooling their resources. Also, in regard to below average workers, I suppose that in many fields a coop could use productivity/skill/experience/etc to scale how big a slice of the pie each worker gets. This would allow any reasonable worker to be hired, while encouraging competitive productivity. It would all depend on the coop's rules.