Sgwd y Bedol - The Horseshoe Falls

We walked up from Pontneddfechan in the Neath Valley to see the four waterfalls. The Horseshoe Falls in the foreground is well-named. I posted recently about water flowing faster in the middle of a stream that towards the sides. There is more drag from the edges. So i wonder whether faster water wears rock away faster and has resulted in the horseshoe shape?