The iPhone headphone jack.

Understand you to be asking why the new MacBook Airs and MacBook Pros have a 3.5 mm headphone jack, but not a lightning jack for the headphones that connect using a lightning connector. Is that right? Well, I'm sure there are lots of reasons that go into such a decision, but I can't speculate on why Apple's designers made the choices they made with regard to connectivity. I mean, I could, but it wouldn't be appropriate or productive. But there are solutions out there that allow one to convert one the of USBC-C ports on today's MBPs and MBAs to allow for a headphones using a lightning connector to be used. For example, today's MABPs and MBAs have at least 2 USB-C ports, one of which can be converted with the help of a third party dongle to allow for a lightning-jack-based headphone to be used. That's just an example; there may well be other options out there that I'm not aware of.

-- JDee

Please write EFFECTIVE Apple Support Communities posts; with actual questions that you need help with.

Apple killed the Headphone jack with the iPhone 7/7+ back in 2016. That was with phones. Apple killed the headphone jack in MacBooks too.. wouldn’t you rather use AIRPODS?

USB-C to Lightning headphones or USB-C to 3.5MM headphones is what you use.

-Christian