> on rasperry pi, can't one just run usbd & usb/* as regular programs, > since usb is not required to boot?
Don't forget you need usb for keyboard and ethernet, which often come into play during the boot process. Actually the pi is a special case because the fat partition on the SD card is guaranteed to be there (for the GPU to boot from). We could have just dossrv in /boot and load everything else from SD. But that's starting to look too much like initrd ... /boot is simple, and RAM is cheap, even on the pi.
