Can you fit your $400 Bose ear buds or your tweeter inside your ear canal the way a tiny hearing aid receiver fits inside your ear canal? You may know a lot about hifi audio equipment but it looks like you don’t know much about the law of physics then.
There’s only so much a tiny HA receiver can do and trying to optimize it for HF amplification beyond 8KHz, even if possible, and likely not, is just not a priority or even practical for the masses of people who need to wear hearing aids and their HF loss is almost total. So your complaint is to the wrong product and the wrong audience.
I think if your HF loss is not total and you want products that can deliver HF beyond 8KHz, you should be looking at PSAP (Personal Sound Amplification Products) instead. You can probably wear them around but they’ll be sticking out of your ears quite a bit. But you can just use them when listening to music only and for normal daily routines, you can wear HAs.