There are physical and psychological consequences not to treat hearing loss. These consequences can be much more important than simply not hearing well. It has been scientifically proven that hearing loss can be linked to depression, social isolation, paranoia and personality changes.
Additionally when not hearing properly, risks of falling are higher. And the more severe the hearing loss, the more likely falling becomes. Dementia is also highly correlated to hearing loss: US studies show that nine patients affected with dementia out of 10 have hearing loss. Likely reason is that hearing loss leads to more isolation which leads to faster cognitive decline.