I had a pair in the early '80s.
They were pretty common in the earliest home computing days when the only "home systems" were S-100 boat anchors, but once luggable computers came along (Osborne, Kaypro) and then PCs, they became a thing of the past.
You could however fit just over 1 MB on a double-sided double density 8" disk. It was a long time before smaller floppy disks caught up to that.