A bunch of people organize and then the boss fires them. Then the boss has no employees to do the work. Ideally this outrages enough other employees to go on strike and in a semi-functional country it would also prompt some oversight on their practices.
The more people organize, then harder it is to just fire them. The more publicly they organize, the harder it is to just fire them.
If they don't organize, the boss just gets to say what they do and for how much money, so that's definitely not a better alternative to organizing long term in terms of "leading to better working conditions".