I see a lot of people complaining that the Fairphone 6 doesn’t have an Aux jack.
Just use an adapter cable.
A 3.5mm Aux jack takes up a significant amount of space just to connect a few wires that could be connected through USB-C anyway, that space could be used for a bigger battery.
Even if there was a good enough reason to keep Aux it should be 2.5mm Aux and not the usual 3.5 as it does exactly the same thing but uses less space
Z space is at a premium too, because consumer studies (according to Fairphone) show that people want slimmer phones. More so than functionality like 3.4mm TRRS.