I'd love an experiment to prove this out. Take a room roughly equivalent in size to an average classroom and containing chairs, desks, wall hangings etc as would be found in most classrooms. Put a target dummy at one end of the room that can measure impact forces to various parts of the dummy. Define "death" conditions for the dummy - not just raw force, we want to allow for things like a knife to the throat.
Have people attack the dummy, starting from the other end of the room. Some participants will be given weapons like guns or knives, others will have to improvise with what's in the room. Measure the time it takes and use health monitoring devices to estimate the level of physical effort the participant applied.
Without doing this experiment I'm already pretty confident that a plot of time to kill will show the group given guns far ahead of the knife group or improv group. After all, they only have to aim and pull the trigger while the other groups have to move across the room. Likewise, the gun group would show far lower physical effort than the others, from the movement across the room as well as the greater need to directly apply human-sourced force. The knife group has to swing / stab / slice with enough force to meet the death conditions. The improv group has to potentially disassemble or rip apart something to then have a sharp or blunt instrument, then they still need to apply their own force like the knife group. Naturally this might change somewhat if we go nuts with the guns, like big heavy rifles or machine guns. Those would require some substantial physical effort. But handguns or the average AR-15? Not really.
Guns are a fast, low effort way to apply potentially lethal damage to a human target. You can absolutely apply lethal damage to a human in an uncountable number of other ways, but they are almost universally slower and higher effort.
Thus, we see frequent mass killings using guns, but knife incidents with high death totals are pretty rare.
Have people attack the dummy, starting from the other end of the room. Some participants will be given weapons like guns or knives, others will have to improvise with what's in the room. Measure the time it takes and use health monitoring devices to estimate the level of physical effort the participant applied.
Without doing this experiment I'm already pretty confident that a plot of time to kill will show the group given guns far ahead of the knife group or improv group. After all, they only have to aim and pull the trigger while the other groups have to move across the room. Likewise, the gun group would show far lower physical effort than the others, from the movement across the room as well as the greater need to directly apply human-sourced force. The knife group has to swing / stab / slice with enough force to meet the death conditions. The improv group has to potentially disassemble or rip apart something to then have a sharp or blunt instrument, then they still need to apply their own force like the knife group. Naturally this might change somewhat if we go nuts with the guns, like big heavy rifles or machine guns. Those would require some substantial physical effort. But handguns or the average AR-15? Not really.
Guns are a fast, low effort way to apply potentially lethal damage to a human target. You can absolutely apply lethal damage to a human in an uncountable number of other ways, but they are almost universally slower and higher effort.
Thus, we see frequent mass killings using guns, but knife incidents with high death totals are pretty rare.