I'm not sure where you're getting the idea that co-ops are supposedly more profitable than autocratic workplaces. Co-ops still compete in the marketplace but they distribute ownership and profit among the workers in a democratic fashion, typically on the basis of their contribution.
The parent comment asked how Amazon could stop systematically oppressing their workers, not how workers could stop being the targets of systematic oppression. Amazon could accomplish this goal by distributing corporate ownership among the workers and giving them a democratic platform to make decisions about their workplace in an egalitarian way.
Presumably they'll do pretty well since there won't be any big bad corporate overlords to steal the value of their labor.