Labor movements are made up of people, yes. Not sure how that is related to unions. Labor organized in every single democracy regardless if there were unions or not. Labor movements tend to create unions, so unions are often a result of labor movements and not the source of labor movements.

>Labor movements are made up of people, yes.

And so if the people in these movements made smaller organizations to advance the goals of the movement at their workplace, in their local communities, and the national level... we might even credit those organizations, yes? Just like we do with the civil rights movement?

>Labor organized in every single democracy regardless if there were unions or not.

Some economies skipped steam power too, but every early industrial economy had labor unions predate modern labor standards.

Not a single one of those unions had legal backing though, they were just political movements and people working together. Not sure why you say they have anything to do with the theatre that are modern unions. Rather the concept of modern unions limits worker power, since it created a lot of laws preventing workers to organize as they wish and instead have to fit the very narrow framework that are modern unions. Workers had more power back then when they were free to organize without the limitations of modern unions.

For example, why even have a vote? Why have enforced term limits for unions that you can't kick them out before the limit is up? Why no bargaining as a group without a vote?

Organizations have bylaws largely because without them, chaos reigns.

A movement that hopes to continue must become an organization, that is, a collection of humans who agree to engage with each other according to an agreed upon set of rules.

Your whole “movement != union” is a distinction without a difference.