Should banks split?

In some countries, banks split due to the regulations. Such regulations are designed to reduce the risks taken by the banks. However, such regulations do not really solve the problem or mitigate the problem. As in Germany, banks do not need to split, but as we see from the last financial crisis, the systemic risk in the German banking sector was definitely lower than that in the American banking system. Therefore, the operation in the banking sector might create higher risk than the structure of the banks does.