The 2008 MacBook Air didn't have an optical drive, so Apple sold a separate SuperDrive accessory, which has finally seemingly been discontinued from sale.
RIP Apple USB SuperDrive
Visit Apple's website, and you'll see the SuperDrive is sold out. That may signify that the ancient device has finally been pulled from sale.
Apple has never been shy when ditching ports, peripherals, or drives in favor of more modern standards or thinner devices. The MacBook Air is one of the more significant examples, being among the first consumer laptops sold without a disk drive.
Apple's solution was one it has gone to many times over the years -- sell it as a dongle. The USB SuperDrive started life as a $99 accessory to the MacBook Air.
The device has remained available and in the Apple Store for the 16 years since its introduction. The price dropped slightly to $79, and no updates were ever made to the product.
Despite Blu-ray being a thing since 2006, Apple didn't support the format with SuperDrive. It also used a USB-A connector, meaning users needed an adapter to use it with modern Macs. And, power provided by that port is a consideration, so most hubs and docks can't drive it.
Technology around optical drives got cheaper and more widely available, so it is safe to say the SuperDrive outlived most of its usefulness more than a decade ago. Users have been able to get much more powerful external drives with USB-C for years and at a much lower price.
The product has sold out on Apple's website, but it is still available elsewhere while supplies last. It can be purchased from Amazon for $77.99.