A keyed drill chuck promotes drilling accuracy by ensuring the drill bit is held in place tightly. Tightened by the key that has a gear to match the chuck's jagged teeth, the chuck doesn't come loose like a key-less chuck does, causing the bit to twist or fall while using the drill.
The drill equipped with a keyed drill chuck can handle heavy-duty projects when needing to secure multiple screws repeatedly, such as when screwing down a deck's planks. When you don't need to change out the bit that often, use a keyed drill and chuck to keep work flowing.
Because the chuck of a keyed drill is made of metal, and not equipped with a soft grip coating, the chuck lasts longer when used a lot. Key-less chucks continually come loose and eventually the soft grip covering wears off, making it next to impossible to use the drill effectively.