According to Wikipedia: Erosion is the process by which soil and rock are removed from the Earth's surface by exogenic processes such as wind or water flow, and then transported and deposited in other locations.
Along some coastal areas this has always been a problem but one that 'naturally' occurs.
We have been watching this erosion process for the past 20+ years down at MacDonald Hill
which is just down the road from from us.
As you can see the grass/earth is falling into the sea.
Where there were once two paths heading down along the edge of this cliff,
there is only one now.
There is not much that can be done that would be practical to try to 'hold back' nature.
Any 'solution' would only be temporary.
Best to respect and admire the forces that 'nature' exerts on us.