Regardless of, but not blind to. Different workers do experience different conditions because of race and gender among other things, and unions need to account for those differences not pretend they don't exist.
> I could in no way trust a tech Union to actually fight for me and not against me
You probably didn't mean it this way, but this strongly implies to me you are knowingly doing things that someone who cared about racial or gender equality would feel like they would need to fight. Why is that?
From my perspective (as, for what it's worth, a cis white man), ensuring all my colleagues have equity is a pretty strong win. I want my company to have the best working conditions possible. That means ensuring that the most talented people feel welcome there, regardless of their demographics. Which, in turn, means removing systemic ways that people from some demographics may not feel welcome or able to take those jobs. Where's the downside?