Without a doubt it adds safety!
Surely I am not the only one who has 1) Flinched from the startup "bang" of a miter saw. 2) Had to adjust material position AFTER a miter saw is running because the material jumped off my mark. 3) Nearly dropped handheld power tools like a grinder or router because of the high torque when powering them on. 4) Been tempted to throw things across the shop (could injure somebody) because the breaker tripped again, or the lights keep flickering from all the tools turning on.