That means that certain products/services aren't a good fit. So I think if you are part of one and you have lofty aspirations for what you are working on, you should plan for the day you outgrow the co-op and need to hire a bunch of people.
However there are some co-ops who make platform software and questions of "scale" might apply there, so maybe some interesting reading? Check out https://www.loomio.org/ - their company handbook is online somewhere.
We chose to use a holding company model for our cooperative https://www.staffing.coop so that we could have many startups and conversions underneath one holding company worker cooperative.
In terms of scaling: You may either form a network or join one. I'm part of Europe based digital cooperative and we're starting to do just that https://medium.com/camplight/accelerating-a-global-movement-... :)
This allows the complex efficiencies of a capitalist corporation, but allows the people doing the work to retain direct control over their local workplaces and not be beholden to investors.
Mondragon in Spain is the most famous example of this.
As such networks develop, starting a new cooperative venture may become more attractive to some entrepreneurs than a traditional startup, which in turn drives growth of the network.
Capitalism is actually very unhealthy from a mental health perspective, so the cooperative model creates the safety net opportunity to take risks and try new things.