I won't attempt to defend the current administration's incompetent and chaotic approach to public health (or communications in general) but it's hardly an existential crisis. The country literally existed for over a century before HHS was even created.
Among other major problems, the logic in your comment implicitly assumes that the worst a badly-run (incompetent, malevolent, or some combination) central authority can be is equal to the effect of no central authority.
Another important error is the implicit assumption that public health risks are constant, and do not vary with changing time and conditions, so that the public health risk profile today is essentially the same as in the first century of the US’s existence.
