I once had a client who was a firm believer in configurability, so much so, in fact that their application had something like 10000 configuration variables. Adding code became tortuous of the overhead of maintaining the configuration application and database. But they swore they needed this level of flexibility because every one of their customers had different requirements, and needed different settings.
But they had only nineteen customers and didn’t expect to grow beyond fifty. That was not a good trade-off”