The answer to 'which is better sump pump or' is that sump pumps are generally better than a dehumidifier for addressing issues with water accumulation in a basement or crawl space. Sump pumps actively remove excess water by pumping it out of the home, while dehumidifiers simply reduce moisture levels in the air.
Sump pumps are designed to automatically activate when water levels rise, preventing flooding and water damage. They can handle much larger volumes of water than a dehumidifier and are more effective at controlling moisture issues caused by groundwater, heavy rain, or other water intrusion. Sump pumps also have the added benefit of helping to prevent mold and mildew growth by eliminating excess moisture.