California can do a lot to private companies, but the supremacy clause allows the federal government to do what it wants. If a business wants to engage in these illegal-in-California practices, they could partner with the federal government.

Edit: Now that I’m doing the research a partnership isn’t even needed, just a contract. Which makes sense, the feds cannot hire a private individual to do what would be illegal for them to do themselves… conversely, a company who is contracted to do federal business also enjoys supremacy by virtue of acting for the feds.