True, but some of those old machines could do amazing stuff with ~huge datasets. Basically by just doing one ~simple operation per data pass. Read, do something simple, write. Then repeat that as many times as needed, with a different operation. Sort of like executing a program one line at a time.
They did crazy tricks because timesharing wasn't invented and whatever program was running had the full machine to itself. Also, designers of these computers usually built everything around the flow of data so that a CPU would have as little as possible to do to read tapes or cards.
