I came to the same conclusion. I know how my mom reacts to news she doesn't like - she defaults to denial. My memory has always been stronger than hers, so there's no shortage of incidents that I remember, that she has long forgotten. (The tree remembers what the axe forgot, after all.) If I were to attempt to bring things up, she'd deny such things ever happened. Instead of me having catharsis and her having self-recognition, I'd be put in a defensive position and she'd say I'm exaggerating or making things up. Which is to say, attempting to have a serious talk with her always makes me feel worse.

Thankfully, I have siblings, and they remember what our childhood was like. We have all given up on trying to get our mom to see the light. Instead, we have a secret group chat where we can vent as needed.