I got an iPhone X recently and it came with this.

It’s the Lightning to 3.5 mm headphone jack adapter. I figured Apple got rid of the headphone jack and came up with this simple adapter to send analog audio signals from the phone to a 3.5 mm jack. Simple, right?

Turns out this thing is way more complicated than I thought. It’s not getting analog audio signals from the phone. It’s fully digital. Someone looked at this thing under X-rays and iFixit wrote up a post about it.

There’s actually a lot going on in there. As expected, one end is a simple female 3.5 mm headphone jack, and the other end is a male Lightning connector. But what’s all that silicon around the Lightning connector end? Most of the retail space near the connector is taken up by a single mystery IC. … While the official purpose of this IC is unknown, at minimum we can guess that it contains a digital-to-analog converter (DAC) and amplifier, and its counterpart, an analog-to-digital-converter (ADC). https://ifixit.org/blog/8448/apple-audio-adapter-teardown/

Whoa. X-rays revealed an integrated circuit inside the Lightning side of the adapter!

OK, so this thing has a DAC and an amp. How good can a tiny little $9 circuit be?

This tiny Apple device has better performance and more and cleaner output than many fancier “audiophile” devices I’ve tested. Apple has more resources to make better stuff than the smaller companies. Most 3rd-party headphone amps and DACs, all be they bigger and far more expensive, put out less clean power into 32Ω loads, and do it with more distortion, poorer sound and lousier frequency response. https://www.kenrockwell.com/apple/lightning-adapter-audio-quality.htm

Whoa! This adapter, which I got for free and costs $9 to replace, has a ridiculous amount of quality and engineering put into it. Can you imagine how much went into making this thing? All of that research, development, and manufacturing? Millions? Maybe.

But guess what? No one wants it.

Here’s just one of the stronger reviews:

Personally, I’m amazed whenever I use it but I always wonder for a moment, “what if Apple just made what people wanted?”