Apple is ceasing production of the lightning adapter connecting to headphone jack which was launched in 2016 with the iPhone 7 and 7 Plus models, with the company’s online stores in most countries, including the United States, listing the adapter as “sold out” recently.
The 3.5mm adapter is still available in a few countries like France, Sweden, Finland, Denmark and Norway and it seems that those are the only places where remaining stock can be purchased. Back then, it was included in the box of iPhone7, iPhone8, and X units with no additional costs, while the adapter could be bought online and was priced at $9, allowing consumers to connect a wired headset that had a 3.5mm plug to their iPhones by using the lightning port, without having to rely on a headphone jack.
A similar situation happened earlier this year wherein the USB-operated CD drive first sold out in US Apple online stores and then was eventually discontinued across the globe.