Carbon steel is lighter but this also has less thermal mass, so it heats up and cools down faster, also tends to have less even heating.

So, searing something quickly on a preheated pan is a bit harder since the pan will cool off faster as the food leaches the heat out. Important for stuff like stir fry’s or steaks where you want short periods of intense heat for good searing at the surface but not over cooking in the interior.