Existing slab is the finish
Cracks, patches, repairs and aggregate exposure become part of the final appearance.
Not every slab is a candidate
Contamination, moisture, previous adhesives and extensive damage may limit the suitability or increase preparation.
Maintenance
Polished concrete still requires cleaning and periodic maintenance; it is not a zero-maintenance floor.
Budget risk
Renovation projects should avoid assuming a perfect decorative slab before existing finishes are removed.
Commercial flooring decisions depend on the actual substrate, moisture conditions, traffic, cleaning regime, accessibility requirements, fire/building rules, manufacturer instructions and local code. This site is for planning and comparison, not installation instructions.