Humans did do it before.

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It's also worth pointing out that the developers at Mozilla literally decided to make a brand new programming language (Rust) that eliminated an entire categories of bugs and started working on a new browser (Servo) where its components could be switched into firefox.

Then Mozilla fired the team working on it.

Lesson 1: Better tools and processes eliminate bugs.

Lesson 2: If you don't have the tools, make them.

Lesson 3: Mismanagement leads to security vulnerabilities.