This is how coastal erosion works in Holderness, the part of the country where I grew up. It averages about two metres of loss every year, but it doesn't lose it two metres at a time. For any given part of the coastline, nothing will happen for maybe five years then suddenly the sea will take a ten-metre bite out of it.
The obvious way to stop this is to build the equivalent of kerbstones. The larger towns do have these — breakwaters and boulders — but elsewhere the cliffs are exposed and they're gnawed away at. Some thirty towns have been taken by the sea since Roman times, four of them off the coast of my home town, Hornsea: Northorpe, Southorpe, Hornsea Beck and Hornsea Burton. In Hornsea itself (which used to be the second-largest of the five villages, behind Hornsea Beck) there's a Hornsea Burton Road that runs perpendicular to the sea: if you carried on in a straight line, you'd end up where Hornsea Burton used to be.
As for why we're not protecting the coastline by dumping huge rocks from Norway along its length, well there are two answers. The first is money: coastal defences are expensive, and although the larger settlements are protected, arable land is not regarded highly from a cost-benefit perspective. The second is that defending against longshore drift tends to move the problem elsewhere: Holderness suffers so that Lincolnshire doesn't. This is somewhat controversial, and came out of a Hull University study in the 1970s or 1980s that basically said to let it happen, the Netherlands needs the extra soil that makes its way there over time.
Oh well. If Hornsea becomes an island surrounded by concrete walls and chunks of rock, that might increase tourism.