Each bullet does the same amount of damage, regardless of whether they are fired 0.1 seconds apart or 0.3 seconds apart. (Made up numbers, but a semiautomatic can be fired very quickly if you aren't taking time to aim.)
This pedantic distinction ignores reality. Police response to a shooter is measured in some finite number of seconds. N / 0.3 is smaller than N / 0.1. Slower fire rate matters.