Before I had this I assumed wrongly that hearing loss could always be fixed by making sound louder. (It doesn't, just sounds like a voice disguiser or someone on Helium talking through a bad speaker.)
This looks promising.
I have a severe sensorineural loss in both ears and wears hearing aids with a lot of success. My loss was the result of some unknown illness when I was younger - a loss resulting from illness or drug reaction tend to present randomly across the frequencies, whereas an age-related loss is almost always a "ski slope" loss, which means the high frequencies are mostly lost and the lowers are mostly fine.
Your experience is very common with new hearing aid users. The aids are able to increase volume at specific frequencies as defined by your hearing test(s) and the other features of the aid, e.g. noise reduction and compression are able to give a great quality of sound. The problem is usually in the person's ability to comprehend these new sounds, i.e. their brain, not their ears. A person with a hearing loss typically takes seven years to try out hearing aids, in those years their brain has got used to not hearing certain frequencies and sounds altogether and it can take time and training to get that ability back.
There is not really a great set of tools for brain training part of the hearing problem at the moment, in my opinion its badly overlooked by the hearing industry.
This is a very interesting book: https://www.amazon.co.uk/gp/product/0262045869
An audiologist should be able to tune your hearing aids to amplify only those frequencies that need amplification.
(Although my understanding is that this is fairly new, and may not be available around the world)
But the serious problem with hearing loss is the "bandwidth", meaning the damaged cells send less information to the brain even if attenuation is compensated by hearing aid, leading to bad recognition of sounds and speech.
An audiologist will typically test someone, see that they need amplications across the range but send them away with a much lower amplification for a weeks to get used to things. Then bring the volume up as time goes by.
People amy also need to get used to the aid's noise reduction algorithms as they can seem unatural at first and is a nightmare for anyone who used to wear an old analog hearing aid with no noise reduction.
So, yeah, hearing aids are rarely plug-and-play from day one - the user needs time to adjust.