It was fairly common in the 1980s to have two #floppy drives because, if you had no hard drive (they were expensive), then the only way to copy from one floppy disk to another was by having two floppy drives.
Having two floppy drives remained common-ish in the early 1990s, for a different reason: there were two different sizes of floppy disk (5¼ and 3½), and in order to read disks of either size, you needed two drives.