It can be built into software systems. Just look at the primitive computer that prevented the Apollo 11 lander from crashing into the surface of the moon, or any of the plethora of real-time systems running critical ops of all sorts where failure is not an option. But those programs all had the financial and power-broker support necessary to get it done.
The problem with software in this respect is simple: People. There are lots of flaky, fundamentally unreliable people out there. Software is a real crapshoot when ordinary buttheads start generating code sans the proper resources and oversight. A government job to program voting machines? Seriously? Good luck with that.
