You're not considering the entire history of the labor movement in the United States, then. There were massive protests, literal battles, and many died, all to bring about better working conditions, shorter workweeks, higher pay, etc., not just for those inside those companies but across the entire economy.

Workers fighting for the rights of themselves and others isn't a new thing. Hell, it even happened in the era of medieval serfdom following the Black Death; there was suddenly a serious shortage of labor, and the serfs realized they could push for reform because the landed gentry now needed them more than they needed the gentry.

Genuine question, but are there many examples from the labour movement where there were labour actions directed at the company's general business practices rather than the rights of the workers working in those companies? It feels like the obvious difference here is that GitHub employees aren't arguing for their own rights so much as the rights of people outside of GitHub.

Genuine answer, you should read books on this stuff. It's a fascinating, complex history, and no one is gonna be able to summarize it well in a low effort Internet comment like I'm making now. But the answer is yes, there are very many.

To pick just one example though, labor unions were heavily involved in the Civil Rights movement, and fought against racist/discriminatory actions by those companies.

The tech industry does have a strong fungibility / "seller's market for labor" advantage.

A software engineer who leaves a position at a company (especially in the cities where the companies we've heard of have offices) is extremely likely to get snapped up quickly by another company, often at about the same salary. That gives individual employees a lot of freedom to exit on ideological grounds that other industries with tighter labor markets may not have.