Zoning by use (residential, commercial, industrial, etc.) is just one of many land use tools. There are tons of rules in Houston about how much land you need for a building and what you can actually build, as well as restrictive covenants in individual deeds that limit what can be built.

We don't need to eliminate zoning, but density-based zoning is guaranteed to cause economic segregation. That's what it's for. We should eliminate it in our central cities and employment centers.