>If you are philosophically opposed to unions, you shouldn't have to pay them at all

You don't. Work somewhere else.

If you benefit from the union's work, you should absolutely have to pay for that work.

Chances are that you benefit from open source code that I wrote. Where is my money?

Well, you choosing to donate your time and effort to an open source project is really not analogous to a union's work improving workplaces, but! As it so happens I do believe that having huge swathes of the tech industry built on unpaid labor is also a pretty bad thing, that the political stance taken by large parts of the FOSS community that "free means no restrictions, EVER!" is foolish, and that companies should have to pay for their use of FOSS. It enables exploitation of individual maintainers by massive corporations.

And to loop back around to the topic most of us are discussing, if there were some type of SWE Guild, standardizing rules around FOSS usage and remuneration for FOSS creators and maintainers should be high on that guild's list of priorities. There're thousands of people in the entertainment industry making comfortable livings off a combination of some work and residuals; why can't that be us? Why shouldn't people who've created, maintained, and improved projects that companies have leveraged for billions of dollars of profit see some of that money?

Well, you choosing to donate your time and effort to a union project is really not analogous to a human's work improving lives by making open source software.

What you said is cool and all but I am still waiting for my money for all of the open source software that you are using.

Sane countries make you pay only if you want to participate in the union (such as when you vote).