In this world of things — houses, cars, guns — loss of life is required for technological advancement. Improvements are not created in a vacuum; without failing somewhere, you won’t know where to improve.
No one thought of seat belts before people crashed their cars. No one thought of bullet-resistant body armor until people were shot. No one reinforced buildings to withstand earthquakes until some fell during earthquakes. You don’t know something will fail until it fails, and you don’t know the full extent of that failure until well after it’s happened. You can extrapolate possibilities and repercussions from prior events and understood logic, but until real-world testing, it’s all assumption, and that testing never ends; there are always new things to try.