But they don't. And won't.
USB C headphones and 3.5mm headphones (and Bluetooth, USB A, etc) are all equally as "analog" as one another (with the exception of someone with all-analog equipment, of course).
You need a DAC somewhere between the chip you're getting the digital signal from and the speakers that are playing an analog signal. And so the quality of that depends on (among other things) the quality of your DAC.
With USB or Bluetooth headphones, the DAC is somewhere in the headphone. With the 3.5mm jack, the DAC is behind jack. If you have a device with a crummy built-in DAC giving you a noisy signal, you'll be better off using a USB DAC.
I haven't used Apple's USB C earbuds, but Apple does make a $10 USB C to 3.5mm DAC that performs very very well for its price point.
Next thing HN folks are going yo want the iPhone to come with a SCSI port.
Also, many people want to run Linux on their phone. About 7 in 10 smart phones run Linux, and smart phones are devices billions of humans use every day.
This is as far from the mainstream as you can possibly get.
Come September it will have been a decade since Apple dropped the headphone port - the world has moved on
Do an experiment. Jump in a pool with both your iPhone and your MacBook and see which one works when you get out.