We have the guiding principle of the reforms to thank for this: risk-oriented governance and 1/4  BIS central bankers' speeches  regulation are there to help banks allocate capital resources as efficiently as possible. But in order to prevent undercapitalisation, this approach needs very specific rules.
This increases the compliance workload – that is, the effort associated with meeting the requirements as well as demonstrating that they’ve been met. The Basel rules were made for large, internationally active banks – they were not designed with small banks in mind.