Back in the days of corded landlines, everyone had a phone in the kitchen. It was desirable for the cord to be long, so users could still move around the kitchen as they chatted. Telephone manufacturers provided a built-in way to keep cords long, yet manageable:

Image: Al Butler

Those are called retractile cords, and they were made on purpose-built coiling production lines. First copper is drawn and annealed into wires. These wires are individually insulated (so they don't mix signals), then wrapped together in a plastic sleeve, either PVC or polyurethane. Next the cords, which are still straight at this point, are wrapped tightly around a long mandrel and baked in an oven, softening the plastic sleeve. The sleeve is cooled in place on the mandrel, having "learned" the helical shape it's in.

Payphone manufacturers, however, didn't have to worry about length, just durability.

Image: Tyler Criso

With the transition to cordless landlines, I'm thinking a lot of those coiling production lines went dormant. And with the subsequent transition to cell phones, a lot of coiling production lines were probably scrapped altogether.

While careful manufacturing attention was paid to corded telephone lines, cell phone charging cables have been treated as an afterthought; all design attention was focused on the phones themselves.

However, a Chinese charging accessories manufacturer called Skegic is paying attention, and has borrowed a trick from old-school coiled telephone cords. This is their MagCable, a 100W charging cable:

It's not made the same way that traditional retractile cords are. Instead, there are magnets integrated at specific intervals along the jacketing, causing the cord to self-coil when it's slack. Pretty smart design.

The MagCable is offered with three different connection options, and runs $25.