Re: What's new?
>you could also buy a landfill android phone built specifically with a small screen and a large battery
Landfill Android devices don't tend to have Bluetooth LE. AOSP only supported BLE a couple of versions ago, though some higher-end Samsung Android devices sported the hardware earlier.
>I would have thought that it would be possible to get similar behaviour at a fraction of the cost using an app and a normal high quality bluetooth audio device designed for listening to music, rather than phone calls.
It wouldn't. These hearing aids contain microphones themselves (not just supporting the use of the mics in the iPhone), as well as containing their own audio processors. All this, and they last for around five days between charges.
Basically, if you are using a device all day every day to help you with all aspects of your life, you don't want to compromise.