The deciding factors are category, volume, and time. Clean water, a small area, and a fast response can be a DIY job. Contaminated water, multiple inches, finished space, or anything that sat overnight moves it firmly into professional territory.
The hidden cost of skipping professional drying is mold and structural damage weeks later. Commercial extraction and LGR dehumidification pull moisture out of the subfloor and wall cavities that a shop vac and box fans never reach.