Almost all the cooks/childcare providers, office support, etc are contractors not employees. A significant amount of SWE and other technical roles are contractors as well.
https://www.cnbc.com/2018/07/25/alphabet-google-employed-mor...
https://www.cnbc.com/2018/07/25/alphabet-google-employed-mor...
For what it's worth, I don't agree with the implication of the comment--it isn't fair to say software engineers can't have any reason to organize or protest against things that their company does.