Zoning laws are a great way to implement social segregation without explicitely saying it too loudly, I guess that's the reason they are so popular in "free" and "open" societies.
Want to prioritize walkability to shops? Zoning is a great way to make that happen.
Want to prioritize keeping noisy things away from residential areas? Zoning is great for that too!
Want to make a socially segregated city? You can absolutely do that with zoning!
Zoning is a super great tool, it's just that the things it optimizes for are sometimes misguided (or in some cases straight-up harmful).