Formally verified, bug free software exists. It just costs a LOT to produce, and typically isn't worth it, except for things like cryptographic libraries and life or death systems.
As the discipline has evolved, the high integrity tools are slowly being incorporated into typical languages and IDEs to generally improve quality cheaper. Compare C++ to rust for example, whole classes of bugs are impossible (or much harder to make) in rust.
As the discipline has evolved, the high integrity tools are slowly being incorporated into typical languages and IDEs to generally improve quality cheaper. Compare C++ to rust for example, whole classes of bugs are impossible (or much harder to make) in rust.