ok, I’ll bite
I understand your question BUT I think it comes from lack of understanding about what HAs are trying to achieve.
A decent pair of headphones essentially allow amplification across all frequencies (as far as the design allows) and almost all ‘volume’ - within the specs of the Headphones. Sure, some have a coloured sound with accentuated bass or highs etc. Also, if you are talking about ‘earbuds’ - most of the decent ones are almost completely occlusive - that is how they achieve a decent bass response. There are SOME that have the option of EQ at the headphone and SOME that have sound cancellation of environmental sounds - but essentially you are hearing the input amplified universally - all frequencies, all volumes.
Unfortunately that does NOT work for hearing loss. It has been repeatedly demonstrated that simple amplification - except in the mildest or simplest of cases - does not achieve SPEECH INTELLIGIBILITY for the HOH. This is for several reasons - firstly the loss is - generally - not universal and equal across all frequencies; secondly there is good evidence that the appreciation of speech deteriorates at the cortical level (brain) after a significant period of time without stimulation, so our ability to ‘decode’ sounds into speech/language degrades - and that degradation is permanent to some extent. So HAs have to do so many other things - and this contributes to the ‘crappy sound’ that people experience - at first. They have to amplify selected frequencies - smoothly- to fit a persons hearing loss. The amplification varies from frequency to frequency to increase SPEECH ineligibility. This is much more than '“turning up the treble” - However - for a HOH person with high frequency loss (say) - that will initially be perceived as a very bright or tinny sound as they are not used to hearing those frequencies in that context. Some frequencies can NOT be amplified sufficiently and then they are either frequency compressed or shifted - another unnatural process that affects the appreciation of the quality of sound - but which may increase intelligibility. As the HOH sound detection thresholds are abnormal and depressed (or elevated - you know what I mean) then a linear amplification for all volumes that would make low volume sounds detectable makes higher volume sounds uncomfortable so the HAs are programmed to provide compression - which can be readily identifiable if you have an educated ear and contributes to sound ‘crappyness’ as well. They also need to ‘work’ to improve signal to noise ratios in differing environments as variable as a loud restaurant and a quiet library.
So - the HAs are doing a SHED load of ‘stuff’ - all in the name of improve SPEECH comprehension and without blowing out your eardrums. The sound they produce is going into a damaged processor/decoder that will never fully recover its abilities to decode the sound.
Add to the mix that the receiver is TINY to hopefully allow an open fit/avoid occlusion - where available and that you are wearing it for 16+ hours a day (personally I could NOT wear earbuds or headphones that long YMMV).
The GREAT thing is that we are very adaptable creatures. After some time (yes- weeks is realistic) we begin to recognise the new sounds as normal and - INTELLIGIBLE. Improved speech comprehension is the result.
Now to show the difference with music - look at a typical HA music program - you essentially turn off much the processing as music appreciation is TOTALLY different. Turn off (lower) compression , remove noise management, remove frequency lowering/compression. Of course the other consideration - we can (almost) objectively asses speech comprehension. We use word recognition scores for example. Objectivity assessing MUSIC comprehension is extraordinarily difficult. It is like describing the colour Red .
Sorry if what I have posted is “Old news” to you BUT I must infer from your question that you do not realise the complexity of what HAs must do compared to headphones…
My advice is read - extensively - on this forum and around the web. The information is amazing. READ the NAL-NL2 prescription guidelines which explains some of the complexities of treating hearing loss; read how people who get a cochlear implant learn to hear again. We live in amazing times