> In my opinion, it seems easier to complement the former to catch issues afterwards (like this article)

Fil-C of course can't magically fix your incorrect program. It never had any defined meaning, but the compiled executable does something and Fil-C will ensure that if the thing it does involves say, a use-after-free at runtime now it exits reporting the error, but it can't fix the fact it's nonsense, that's not their purview.

There's no point in hoping that somehow Programming Languages will overturn Mathematics. I mean, I can't blame you for trying, Bjarne Stroustrup is a professor and still seems to think that should be attempted, but it's futile. We're definitely talking "Why can't I extinguish the sun with water?" level thinking.

Obviously I can't speak to your own experience but for me certainly Rust is easier than C++.