Those unions aren't specific to one company/team though and are mainly to set pay floors because they work in a glamorous industry that people are desperate to get into and so they are used to raise the people outside of the competitive spotlight pay in the industry. If you want to start an non-company specific union for developers, by all means, start one but I see no reason to join it considering the only reason people are desperate to be developers is because it pays well.

What a software engineer union would be like depends on who you ask. Thus the risk as no one agrees and thus the result would be a crap shoot. Worse, it'd become a political situation so even if it starts aiming for A the movement may be hijacked to cause B. For example, many people mention preventing things such as unexpected PIPs and firings which sounds a lot more like teamsters than a guild.

Most people don't find it reasonable to sabotage yourself based on the belief that things could be and probably will be worse some day. If some people do, then they inherently tend to get marginalized.

My dad was an engineer who I was told tried to organize a vote to form a union at GE pre-Jack Welch. It failed, but was close. Probably over 30 years after he died it occurred to me that might have something to do with why he retired early.

I always figured any company that has a union deserves it - but that doesn't mean I want to be a part of a company where management and labor has that bad of a relationship. Now I belong to a public sector union - and everybody hates those - so I tend to take a nuanced perspective, but there are some mundane drawbacks. For instance, before covid, work-from-home was pretty restricted, and because the exact amount and rules were in the contract, it wasn't easy to change.

So you're advocating for a union that pays a premium for those employees who have seniority but whose skills are no longer in much demand? At the cost of salary for those whose skills have remained in demand or who have kept up to date with trends? After all, otherwise what advantage does a a union have in your scenario?

I doubt many well performing SEs would be happy to have coworkers like that in the future.

The ones worried about future marketability have many options including saving a lager percentage of income, investing money in passive income sources, moving into management, etc.

The first sentence is true. The second sentence can be true but often isn’t. If 90% of the workers at a firm are worth $50,000 a year and 10% are worth $200,000 a year a union will represent the average worker, screwing the top 10%. The closer you are to the average of the members in your union the better they represent your interests. If you are far from a representative member the degree to which they will fight for your interests is markedly less.

This seems to presume that the members of this group have common interests to negotiate on (they dont) and to ignore group psychology.

If I have high individual negotiating power and I want to, say, work from home then I do not benefit from unionizing with a majority of people with low-power who do not want to work from home.

it's quite plausible that the minimum common interests the group has are already satisfied by the employment terms, and then, the negotiation is an opportunity for "union reps" to game the system to the advantage of some over others.

You iterate this over a large number of negotiations, thrown in "union" as now a group and not a mere negotiating block, and you get the police union.

Yeah but people don't care about limiting their employer's ability to make contracts. Only their own.