what's the issue here? if you buy large headphones from the same company you buy the your phone from, in a future where fairphone no longer exists (which playing the odds, is likely) at some point your also no-longer-supported phone (which functionally becomes slower every year because mobile application hardware requirements appear to double every year) might advance to support new fancy bluetooth things your headphones don't support?

I honestly (not hyperbolicly) don't see how a phone not having a 3.5mm jack is relevant to the headphones _having_ a 3.5mm jack

If the headphones are meant to be used with the phone, then the idea that the headphones are future-proofed because they have a 3.5mm jack is pretty meaningless if you can't connect them to the phone with that jack.

In 2023, most people who give two shits about running wired headphones are using a USB DAC, even if their phone has a 3.5mm socket as the onboard AD/DA chipset is usually mediocre and struggles to drive most high-end cans.

It's not about high-end or whatever. It's about whether these headphones are going to be usable at all in 5 years' time.

And they will be if they're sound in terms of construction and somebody is willing to spend a few dollars on a USB DAC.

By your same logic, if you need to use dongles with a brand new MacBook, today, is the MacBook thus not useable?

I see the small number of ports and reliance on dongles as a big mark against the MacBook's sustainability, yes.

If ultimately you still need to plug something in, what makes it less sustainable exactly?

(I don't use a MacBook in 2023)

If you can't use thing A with thing B unless you also have thing C, to my mind that obviously reduces the expected lifetime of being able to use the combination, especially when thing C is a third party part.

It’s simplicity I terms of construction and standard. Here, the older standard (3.5mm jack) seems stronger (not an expert but an user opinion) and easier to source than usb c.

Generic usb-c to 3.5mm adapter for a few dollars, stick it on the end of the cable and leave it there. Problem solved.

The only person that I've ever seen do that had to replace his USB socket after a few months. It turns out that USB C is not designed for long term constant torque being applied, as is the case when it has a dongle attached constantly in a pocket bouncing around. Perhaps if someone sold a dongle that sits flush with the device, and is secured such that no force is transferred to the socket, that would help.

The dongle solution seems to only be good for sitting at a desk. Not for a device that is literally called "a mobile".

The headphones also work over a USB-C cable.