An argument could be made that with the advancement in technology cars are safer because of the better designs in tires, braking systems, suspension, etc. this allows us to travel faster and stop better. Although this may be true, when speeding it means you have less reaction time and need more stopping distance.
Ignoring the speed limit is like eliminating safety. You increase your stress level when driving too fast; this can’t be good for you. How much time does it really save you to speed? Wouldn’t you be better off arriving at your destination