"Not all software needs meticulous careful human review" is exactly the point. The question of exactly what software needs that kind of review is one whose answer I expect to change over the next 5-10 years. We are already at the point where it's so easy to produce small but highly non-trivial one-off applications that one needn't examine the code at all -- I completely agree with the above poster that we're rapidly discovering new examples of software development where output-verification is all you need, just like right now you don't hand-inspect the machine code generated by your compiler. The question is how far that will be able to go, and I don't think anybody really knows right now, except that we are not yet at the threshold. You keep bringing up examples where the stakes are "existential", but you're underestimating how much software development does not have anything close to existential stakes.
You're right, human review and thorough design are a poor approximation of proving assumptions about your code. Yes bugs still exist. No you won't be able to prove the correctness of your code.
However, I can pretty confidently assume that malloc will work when I call it. I can pretty confidently assume that my thoroughly tested linked list will work when I call it. I can pretty confidently assume that following RAII will avoid most memory leaks.
Not all software needs meticulous careful human review. But I believe that the compounding cost of abstractions being lost and invariants being given up can be massive. I don't see any other way to attempt to maintain those other than human review or proven correctness.