Those are actually at the point of use and unavoidable. I mean extra ones that convert to 5V and then send the power back out elsewhere. All those drives and USB ports still need 5V and the best place to make it is the PSU.
Why is the PSU the best place to make 5 volts? In the distant past it made sense because it allowed some circuitry to be shared between all the different voltages. Now that is not a concern.
