Well, for instance, some amount of power to bargain for better treatment and basic protections, like say a healthy/safe workplace where you don't have to worry about being harassed by a superior and then ignored by HR.

Right now, companies like Uber can treat workers poorly -- apparently at a policy/organizational level even -- because the only thing they feel they have to fear is a bit of bad PR. No one has these workers' backs. HR is concerned with protecting the company. And the workers likely don't have the time, money nor stamina to fight a huge corporation with a lawsuit.

That's why workers need to band together to look out for one another. The deck is already stacked against them.