No interviewing system is perfect or even good. Having said that interviewing, in my experience, isn't actually the biggest problem companies have with hiring. The biggest failures are when you have that realization that someone isn't working out where most companies don't have the stomach to deal with the problem decisively through candid feedback/conversation or possibly letting that person go. This natural shyness around confrontation hurts everyone involved including both the employee in question and all their team members.