As a woman myself, I don't see this as a slippery-slope argument like you're implying. The gender pay gap is very complicated, and IMO not at all the same as a company saying "we want to offer salaries that compete with your local companies, and then also offer these other benefits like working from home" vs "we want anyone within the company to make the same amount regardless of where they live".

The gender pay gap is a whole separate matter that I'd prefer not to get into because, tbh, talking about it in tech-spheres that are still male-dominated is intimidating. I guess all I can say beyond this is that if you're ethically against these practices then I support you voicing that, and while I can offer differing opinions, I still think you're within your right to openly disagree.