I don't consider a cartridge to be truly obsolete until all the major U.S. ammo manufacturers (Winchester, Remington, CCI/Speer, Hornady, Cor-Bon, and Federal) quit making ammo for it.
Do you think any U.S. manufacturers are still making 38 S&W? Magtech seems to be the only brand still available. Maybe one of them will make another batch in a few years when they catch up on back-ordered .380 ammo. I suppose floppy disks aren't truly obsolete since you can still buy them for your Pentium computer.
Both Winchester and Remington still make it. With the exception of very popular calibers like 9mm, .40 S&W, .45 ACP, .38 Special, .357 Magnum, and .44 Magnum, most ammo makers only produce ammunition in runs at certain times of the year. Prior to the great shortage of '08, even .380 auto was still made in runs. Just because something is backordered (as many calibers seem to be these days) does not mean it's completely obsolete.