The side walls to the goat’s hoof grow faster than they wear down and so need to be trimmed. And they need to be trimmed by you.
In nature, the walls would get worn down and naturally trimmed by the rocks and rough ground that the goats love climbing on. If you don’t trim their hooves. the side walls grow long and the curves around and over the sole of the foot creating a place where dirt and debris collects and begins to rot. Basically, you need to trim away places where dirt and other crap collect and begin to rot.
Here is HOW to Trim a Goat’s Hooves from Fias Co Farms.