* Bluetooth headphones are a nightmare to temporarily pair to devices.
* AUX is a standard available on all devices in decades.
* Bluetooth headphones needs to be charged.
* Blueetoth headphones have a very limited lifespan because you can't replace batteries in them.
* AUX is quick, pairing to your friends car for a 15 minute drive - nope.
* Bluetooth is quite buggy. AUX is not.
As someone who has bluetooth headphones, bluetooth in car, wifi casting at home - lack of 3.5mm is still a deal breaker. I'm so happy my new phone has it (last one had an adapter that I couldn't bring with me constantly (oh and it started to glitch on me after a year...).