What is so unsustainable about bluetooth? It has been around for quite a few years. They even offer headphones with replaceable battery and parts which should last at least as long as the phone: https://shop.fairphone.com/fairbuds-xl
Their headphones might have a replaceable battery, but headphones do not necessarily need one at all. Their earphones even have a baked in battery that is not replaceable. And in general, not having a headphone jack pushes consumers to buy bluetooth devices, of which almost none have replaceable batteries (the fairbuds-xl are the big outlier). It's an ecological disaster.
anecdote: had a ten year old premium car with "bluetooth" but could not manage to pair it with anything - supposedly the used bt-standard is outdated or something