This is actually really interesting. When I was young and stupid I decided to walk from Brighton to Hastings (about 13 hours). And what struck me at the time was that you simply couldn't walk the coast, which I thought was a bit weird. Now I'm old and stupid I'd like to do this whole route. I bet there are people planning to walk/run it.

World's longest coastal path opens in England to the public

https://www.bbc.co.uk/news/articles/cy0dxexdd8xo