Sure, but if people don't make any serious attempts at creating something completely new, how do we know we're not stuck in a local minimum in terms of what OS

Sure, but if people don't make any serious attempts at creating something completely new, how do we know we're not stuck in a local minimum in terms of what OS tech we could have? Or do you mean in terms of not using a "safer" language like Rust? I assume its because its not what the devs working on it know.