Does anyone else have parents that were at best neglectful and at worse legitimately evil? Now that I have kids of my own, I finally see that my upbringing was not normal. Does it ever help to talk to them about their behavior towards you and tell them they hurt you? (Cont. in post below.)

Neglectful. No point , I’m doing better w my own kids.
Yes. Hit with hands and belts. Lots of yelling. Emotional neglect....and more. Therapy has helped immensely. I don't need or want an apology: it changes nothing and means nothing. I am very, very low contact and am very happy with that. Please consider therapy, OP, and don't let your kids near them.
They sound very toxic, and I'm wondering what you are getting out of continuing the relationship with them. You deserve better and should not tolerate anyone treating you that way.
so why interact with them at all?
Op- Random examples are medical neglect (not taking me to the dentist for years, refusing to take me to a psychologist when I had severe eating disorder or after I tried to kill myself); they‘d let me go over to boys houses without knowing anything about the parents or what was happening there; never celebrated my high school or college graduations even though I graduated with honors in both—it was future MIL who took me out to lunch and got me a graduation gift for college; mother would hit & kick me. They are still assholes to me.
help in what way?