The I/O size is a reason why it’s better to use cp than dd to copy an ISO to a USB stick. cp automatically selects an I/O size which should yield good performance, while dd’s default is extremely small and it’s necessary to specify a sane value manually (e.g. bs=1M).

With “everything” being a file on Linux, dd isn’t really special for simply cloning a disk. The habit of using dd is still quite strong for me.