First, you have to look at the present infrastructure situation. If the infrastructure is obsolete, that may already be part of the answer. Perhaps we should examine the situation and improve it to make the shorelines more resilient.
On the other hand, we're seeing receding natural shorelines that aren't protected. However, they nevertheless meet certain ecosystem objectives, contributing, in particular, to sediment transport along the shoreline. That prevents a certain upstream deficit.
So the response isn't perfect, but our knowledge of the situation isn't perfect either.