I’d bet it actually is more sustainable to not include it tbh, plus it is likely more affordable.
Mmm now you’re dealing with powered devices that have another two batteries that wear out, plus the battery in the charging case, all the electronics involved, etc etc
Vs a simple plastic connector and an associated amplifier IC that costs about $3 in quantity.
You can still use a wired headset if you so wish with your $3 connector. But when someone wants wireless, it’s nice to have the option.
I don’t blame Fairphone trying to make their product less expensive to produce. It’s not like they’re the biggest sellers in the world or benefitting from economies of scale as much as other companies.
So what you’re saying is the existing crowd with the existing hardware should buy the adapter cable, which if you want to talk sustainability, is more resource intensive to produce than internal phone components, using considerably more copper/PVC/etc by having two connectors in it.
So that the crowd with Bluetooth, which is pretty much provided by every phone wifi chipset by default and is no doubt provided by a chipset like that in the Fairphone, can use Bluetooth.
I don’t blame them that much for trying to reduce costs/component count. But I do wonder how many potential customers a manufacturer who is trying to promote freedom of choice/software loses when they remove a particular freedom/choice from their phone.
Removing the headphone socket does grant an extra degree of waterproofing. You don’t have to make that area of the phone quite as robust either - a 3.5mm plug has quite a lot of leverage on your PCB when it’s plugged in. There’s now room on the PCB for … something else they need/want to put on there, another ram chip, a cubic centimetre for extra battery (which apple tried to justify as their reason), something like that.
But it does mean that they lose at least a few people who like the general simplicity of a wired connection.
Your first paragraph is wrong imo. A minority of users are using 3.5mm jack, including a port on the phone for all users results in more waste than having that minority buy an adapter that can be re used on any phone in the future.
Also please don’t argue that jack users aren’t a minority now. Most users don’t care about having the port on their phone, and most are happy with wireless.