This is a great comment. Your point "dont really think that software engineers could benefit much from unionization" I disagree in one respect: hours and time of day worked. If rules exist that mean you dont work weekends or holidays or more than 50 hours in a week you as an engineer could simply cite rules amd say no. Rules could exist for who has to work those times...
Software engineers haven't evolved enough to realize developers and engineering managers both are highly replacaleable cogs in a software factory. Until influential teams (Devs+Mgrs) that work well together learn the value of sticking together, software unions won't take off.
I know "if you don't like your job, find a new one!" is a tired cliche that often gets thrown at people complaining about legitimate grievances, but software engineering is one of the few fields where a good employee can fairly easily leave for greener pastures whenever they want, at least in the US.
Software engineers are not standing on a work line waiting for a minimum wage job where they have no control over their working conditions. Software engineers create value directly with little or no dependence on capital. Their employers need capital to support whatever their business ops are, but creating software itself requires no capital other than the training and experience that belongs to the engineer.
Software engineers already have a lot of leverage. If you have a boss telling you you have to work crazy hours just say no. If you aren't using the bargaining power you already have a union is probably not going to help you.
In unions bosses break the rules continually and you only get them enforced by persistently filing grievances in the face of a lot of blowback, sometimes from the upper echelons of the union itself because they don't like people rocking the boat too much.
In the grievance game management and union sit down every month or so and take the list of proposed disciplinary actions against employees (firings, suspensions, etc) and the list of grievances filed against management and swap them out to prevent the people with the most seniority from getting fired. A lot of valid grievances will get ignored because they were traded out so some old timer could keep their job - not exactly the epitome of justice.
Having a written contract does provide leverage but not as much leverage as being able to tell your boss that their project will fail and they will lose money if they don't give you what you want. Not every software engineer is going to have that kind of leverage but if you want it you are probably more likely to get it by using your existing skills than by trying to organize a union.
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