In the vast majority of cases, concept of Undefined Behavior shouldn't even exist. All behavior should be defined. We have massively powerful machines and the

In the vast majority of cases, concept of Undefined Behavior shouldn't even exist. All behavior should be defined. We have massively powerful machines and the performance advantage mostly doesn't outweigh the potential damage. And other languages, like Rust, even eliminate lot of UB without a lot of overhead. There are exceptions to every rule, of course, but we need to re-evaluate our priorities as times change.