isn't this essentially a state broadcaster? You might get one decent show but the committee and bike shedding mostly gives you terrible niche programming that's unsustainable without massive subsidies - and most still show adverts.

No, I don't that a cooperatively run streaming service needs to have a monopoly on the legitimate use of force in a given territory. There could easily be multiple competing cooperatives.

State broadcaster are usually funded from state funds (taxes) not voluntary memberships. Furthermore, taxpayers don't usually get to vote directly on what content should be produced. With cooperatives, there could be multiple coops that focus on different groups. They could even join together on productions across coops. Sounds like a good plan to me.