Access to capital whilst remaining a coop is the big problem here - speaking as a former cooperator
All of this is possible in the current economy – Many companies are founded by employees. However, I'm personally comvinced they are not efficient, neither in decision-making nor in usage of the workforce. So what happens to them, and why aren't they the most common form of employment? Maybe some don't keep their form of cooperative decision-making, maybe others never make it big on the market, maybe creators of such companies don't intend to become AirBnb or Amazon and prefer a lifestyle business – all in all, traditional companies still dominate them.
I think it's because being a cooperative is not a stable state. You can go cooperative->traditional, but it's much harder to transition from traditional->cooperative.
Ultimately, a hierarchical society is instinctively easy to grasp, while a more fluid mostly-equal one is not. People still instinctively understand hierarchies better than full-on democracy.
> People still instinctively understand hierarchies better
instinctively? Citation needed. If anything, humans are wired to interact in small and non-hierarchical groups.
The Valve system just leads to cliques and making it tough to get things done.
Maybe instead of pay defining where you are within an organisation it's how much vote you get in the business. And obviously you can engage in peer to peer performance review system like Valve. To be honest I'd only ask one question; How much do you want to work with X again? 0 - 10.