There are still requirements for the types of use classifications (including things like parking minimums[0]), there are still food safety regulations, etc.

The lax zoning laws doesn't mean there are no rules, just that there are no rules preventing you from having an eatery right next to an active oil and gas well right next to a townhouse right next to a liquor store right next to a welding shop.

[0] https://www.houstontx.gov/planning/DevelopRegs/docs_pdfs/par...