This perspective is frustrating, as it paints unions as an entirely negative endeavor. They're not and there are trade offs. Those trade offs may be a net positive or a net negative, but only highlighting the negative doesn't do any good.
>with its own politics and power struggles and debates and meetings... A union doesn't even necessarily act in your interests. It acts in the interests of the majority of members
If your going to chastise the process of advocating for your views then complain that somehow they don't get taken into account then I don't know what to tell you. If your concerned that the interests of other members are outweighing yours, then participate. If you don't want to deal with it, don't join the union.
>people taking a paycheck from your union dues
Oh my gosh, contributing to something that you get value from... what a crazy concept. If you don't get value from the union, then see above; change it or don't join.
>Right but what if your colleagues what these BS work rules?
Why does the assumption automatically go towards "unions would be TERRIBLE"? Most devs don't like to put up with BS, so why do you think a union made up of devs would somehow institute a ton of BS rules just because it's a union. Again, if you don't want BS union rules, then make sure the union doesn't institute them by actually participating.
>What if you're junior and they want pay by seniority?
I hate to break it to you, but that's called the real world.
At the end of the day, a union is about shifting the balance of power and advocating for the things the union sees as valuable. What are the things you'd change about tech employment if you could? How could a union be more effective at achieving those changes? A union doesn't have to just be focused on pay scales and bureaucracy.