Imagine not reading for 10 years because of bad eyesight, eye glasses do not make it so your brain can read, but instead makes it easier for your brain to see the symbols. your brain still needs to decode and comprehend them.
Our hearing system is far more complicated. You can look in the direction you want to see....but you hear all around you, even through walls.
You cannot stop hearing, even in your sleep. It is far more crucial to our environmental awareness than more people realize.
In your analogy, it would be like if my vision got worse and I got eyeglasses which partially restored it, but mirrored everything upside down with tons of static. Now I've got to learn to read upside down and tune out the static, but don't worry because I get 10 free lessons with a reading instructor. Oh and none of this was clearly explained to me or part of my expectation when buying glasses.
And once you put on your glasses everything is brighter.
You need to adjust to the change, and then slowley adapt.
Now what if putting on the glasses meant you saw far more on your peripheral vision?
This too would be a big change and a barrier to getting better.
Hearing aids are the exact same. It's slightly unnatural but once you learn how to use the tool, it's a super power. I can hear conversations in crowded bars when normal people can't. Loud noises compress in a pleasant fashion. I just have to get used to some occasional spatial distortion and subtle flanging
Or, alternatively, it's exactly what I said and the device + audiologist combination just isn't up to correcting a lot of common hearing issues. That seems far more likely than the vast majority of people doing everything wrong.
Sounds like the calibration needs to happen in the home, not the doctor's office.
Of the people I know who have gotten hearing aids, every single one of them was disappointed. Every single one of them still had trouble hearing. As far as I can tell, the only thing the audiologists appear to be able to be able to correct for (with current hearing aids) is "make it louder". If more than that is needed, it's a vicious cycle of taking it home, realizing it's not really helping, and bringing it back to try a new one.
The above seems to be particularly true when the hearing problem is heavily weighed towards not being able to hear certain/higher frequencies, so can "hear" people talking, but can't understand it; especially if there's any background noise at all.
I sympathize that your job was hard and that the clients made it harder. But the clients following directions and trying multiple different hearing aids ... doesn't really solve the problem in a lot of cases. Hearing aids are very expensive, far too expensive for a result of "I still can't understand people talking to me".