If you think Rust provides "Proven because the compiler validates every individual unit." you are seriously uninformed about what Rust's memory safety guarantees are, what they are safe against and what they are not safe against.
Rust prevents sill memory use errors, like out of bounds array access, use of after free, dereferencing null or invalid pointers etc, etc. It also provides a great type checking system.
Of course catching such silly mistakes in a huge thing, a great benefit and will of course prevent any security vulnerabilities and other bugs that such mistakes give rise to.
However it does not prevent you from making logical mistakes in your code. You can still make an infinite number of other bugs. The it comes to security there are many ways to leave holes and vulnerabilities even if your code uses memory perfectly.