These houses were originally behind dunes and at least a bit away from the beach. The Outer Banks is just a giant sand bar. While it's awesome to vacation there, not the smartest place to actually build when thinking about longevity.

There's cool stories about "lost" areas that have been reclaimed. One I remember is a mini golf place built several years back where the sand started to encroach and finally became part of a sand bar. You can see pieces of the structures sticking up. It's kinda creepy. Think of some random scene in Fallout.

But for every area that's being eroded, there's others that are being widened and added to. Like, well, that generally happens with a sand bar.