ELI5: as far as I know, „safe“ programming languages are able to avoid memory related issues that are/were prevalent in C(++). Is this actually the class of bug that causes most security related issues in the browser?
How do you carry water in a sieve? That's the personnel cost analogy to have safe cpp. His point is not about replacing the sieve, it is about having the money to still have some water across even when using sieves.