I don't think I'd join or support a software union even though I think unions are a good idea in general. Software engineering is one of the few careers where the market has actually forced a decent balance between labor and management.
Realistically, unionized software engineers would make hilariously less money than FAANG people are making right now. At least, that's what I'd assume from looking at how things work in Europe.
All right, to steel-man your argument: Honestly, I think even your lowest-brow code camp copy-paste monkey is in a pretty good spot nowadays in the USA. It's easy to make a six figure income just churning out CRUD apps for 40 hours a week. Any company that won't pay up gets disrupted into oblivion by ones that will. (Or it just clunks along forever with a bunch of underpaid workers churning out low quality crap, like what we see from government/hospital systems. Either way, everything's fine.)
What do you want out of a software union?
(Keeping in mind that we can comfortably afford and demand basically any perk you can imagine.)
Realistically, unionized software engineers would make hilariously less money than FAANG people are making right now. At least, that's what I'd assume from looking at how things work in Europe.