This is a traditional technique of splitting oak down to usable sizes before the invention of mechanised sawing. This is how the Vikings did it!!! Wedges are knocked into the end grain of the Oak along natural growth lines.
I feel it still very much has a place in the production of quality contemporary furniture. You are splitting the wood along the cells of the grain rather than cutting through the cells which keeps all the strength of the timber intact and resistant to water because there are no open cells.
For me one of the biggest benefits are the shapes the technique produces. When knocking the wedges into the timber the split naturally follows the internal shape of the wood which often makes for interesting gentle curves and twists. This is then carefully incorperated into a piece of work to produce a unique piece of handcrafted furniture (as shown below). Only can that shape have come from one tree, it can never be repeated again.