Try working in military applications, aerospace, tax software, medical devices, banking. Making one mistakes can affect the fates of hundreds if not millions. It's way more responsibility and risk than the job you quote.
By the way. A dentist gets to try on fake tooth before drilling a real tooth. They actually don't have a choice, that's part of the mandatory training. Doctors gets to train on real people too, medicine schools go to great length to procure bodies for training purpose.
In programming, one would be lucky to get any sort of test environment.