I’ve worn hearing aids in both ears since I was young so I can understand. Its probably been the last couple of generations the tech has got to a decent place and that’s after nearly 30 years of wearing them.
The problem I find with most older people who acquire hearing loss later in life is shame or similar feelings, even if they say otherwise. If you have a good audiologist when you get hearing aids you’ll do real ear measurements. It can often take multiple trips to the audiologist, doing these test, to calibrate hearing aids properly. My partners mother is like this, where she hasn’t gone back since her initial fitting and as a result stop wearing her aids all the time.
My suggestion to anyone with relative like that is to do anything short of booking the appointment for them to get these real ear measurements done. Do them until the sound matches expectations. These device are expensive; so people have every right to take them back until they perform as expected. This includes sending the aids back and getting a replacement/different aid if needed. You wouldn’t drop several grand on a TV and just put up with it if the picture quality was shit. I have the phonak audeo which were expensive but sounds amazing, which is different for my degree of hearing loss.
Phonak and Signia are known brands with Signia (formerly Siemens) being in the space for a long time. If your country has it, try the government funded audiologist. Happy to answer any questions you may have.
Below is a photo of what a REM looks like, show your relative and ask if he’s had them. If not (change audiologist immediately) ensure they get them done until the hearing device perform as expected. Any time they don’t, tell him write down how and inform his audiologist (I would always forget stuff when I was at an appointment). Most audiologist are not only good at their jobs but passionate about it and will try their utmost best to rectify issues you bring to them.
They place this on your ear and then you put in hearing aids. They then play different tones/noises to monitor how you hearing aids perform. It may take multiple visits but it is worth it.
My post was long so I failed to but thanks for mentioning mandatory trials. They’re definitely a huge factor and something we do here across the pond too.