Inequality in Silicon Valley Tech is largely a MYTH.
Once you account for differences in skill, expertise, etc, within the same company, inequality converges to ZERO (e.g.: Level-7 engineers at Facebook, working on the same product, will get pretty much the same package regardless of their gender, ethnic or religious background; same with all other companies; is your skill/expertise level that assigns you to a salary band or another). And this is what true equity and meritocracy looks like. You can’t expect that a junior tester to get the same pay as senior architect or a VP of engineering.
As for the people who cook or clean, they are much more likely to be employees of companies who provide such services to the tech companies, rather than to work for the tech companies themselves.