Driving screws, bolts, long fasteners efficiently — Because of high torque and impact mechanism, screws go in (or bolts loosen) more easily than with a regular drill. Great for wood framing, decking, carpentry, metal works.
Handling tough materials or heavy fastening tasks — Dense wood, thick fasteners, metal sheets or structural screws: impact drivers shine when regular drills stall or struggle.
Speed when driving many screws/bolts — For repeated fastening, impact drivers are often faster and less tiring than drill-drivers, because you don’t need to apply as much downward pressure.