"true safety" like "true Scotsman"? Realistically, you get "better safety". Operator knowledge gets you better safety. Better languages get you better safety.

"true safety" like "true Scotsman"? Realistically, you get "better safety". Operator knowledge gets you better safety. Better languages get you better safety. Better libraries get you better safety. Better testing gets you better safety. Often, each of these has diminishing returns, but that just means that the best outcome is one where don't over-focus one at the expense of others.