I have to agree that people don’t change. I also grew up around dysfunction and have only recently fully realised the extent of it. Like, I knew something was off about my dad (and his parents) while growing up, and thought my mum was ok at least, but now after having counselling I see that certain aspects of her parenting style were toxic. I do have compassion for her, but not as much as I might have, if our relationship had been healthier.
And, as with my mum, with some people it’s difficult or even impossible to have those conversations around expressing anger/hurt in the first place, because they get defensive and shut things down.