And zoning didn't exist then. Zoning was created purely to keep black people out of neighborhoods. The first zoning attempts were entirely race based - SCOTUS overturned them in 1918. The same group came back and recreated zoning to keep apartment buildings out of white neighborhoods. The funny part? "Single family" zoning explicitly targeted black families, who didn't have the wealth for a house, and would buy larger houses as a two or three family collective.
Industrial zoning came much later, as a post hoc justification, long after that was an issue.
Just to stress that the world is larger than the US. Zoning exists pretty much everywhere and the reasons for its introduction were diverse and mostly about quality yof life, citizen health, or city esthetics (keeping polluting businesses out).I have no view on whether what you're saying is true for the US, it is however definitely false for most other places.
Industrial zoning came much later, as a post hoc justification, long after that was an issue.
Zoning truly never has.