It lets them negotiate rules about not firing people without notice, and is otherwise highly correlated with being the kind of place people don’t want to quit without notice.
It also gives them power to be able to make other demands, such as (for example) being given enough time to properly document processes and get cross-training and such.
Unionization doesn’t magically allow everyone to know everything about what happens at your place of work.
It lets them negotiate rules about not firing people without notice, and is otherwise highly correlated with being the kind of place people don’t want to quit without notice.
It also gives them power to be able to make other demands, such as (for example) being given enough time to properly document processes and get cross-training and such.