[kibwen]

> The vast majority of rust programs don’t need such validation.

The vast majority of Rust programs would benefit from such validation existing in the language, even if they never bother to explicitly leverage it themselves. For example, a non-panicking effect would be beneficial for both compilation times (don't bother pessimistically emitting unwinding glue for the enormous number of functions that don't need it, only to attempt to optimize it away later) and runtime performance (the guaranteed absence of the aforementioned glue reduces potential branch points and code size, which leads to better inlining and vectorization).