It is possible to build such reliable systems, but it is not economical for the vast majority of software that gets written — at least with current tools.

If getting something production-ready takes X time, making sure that thing doesn’t ever need to be restarted takes many times X, not to mention the huge investment in testing to ferret out those rare edge cases that cause hangs or inconsistent state.

Someday when software engineering comes into its own as an actual profession, maybe our tools will also achieve a higher level of consciousness, as it were. But nothing mainstream today comes close to enabling this.