Why is Rust then insecure by default, with exicit unsafe blocks leading to type and memory unsafeties, plus blocking IO leading to concurrency unsafeties? They

Why is Rust then insecure by default, with exicit unsafe blocks leading to type and memory unsafeties, plus blocking IO leading to concurrency unsafeties? They are talking about actually safe languages, secury by design and secure by default. Which would be a lisp or scheme without an FFI, or a beam language (Erlang, Elixir). Or pony, without the FFI. Or Concurrent Pascal, not Go. Or a safe scripting language