You're creating so many assumptions that nothing you've stated could be concluded to be an honest reflection of reality. Nobody has to know the rate of leaks,

You're creating so many assumptions that nothing you've stated could be concluded to be an honest reflection of reality. Nobody has to know the rate of leaks, it's irrelevant. Gross negligence is not necessary, how would you even know? Leaks by definition are rarely exposed, we only see some of them. A "highly sensitive" key doesn't mean anything. Assigning more words to it doesn't somehow change the nature of it. Humans are bad at securing things, that's why the best security is to not have a system that requires it. Whatever hypothetical solution you have would be crushed under the weight of government committees and office politics until your security measures are bogus.