I think the key breakdown here is that we're disagreeing on the meaning of forgiveness.
You say "To forgive is to accept." I disagree with that. You can forgive a wrong without accepting it. Because forgiveness isn't for the other person, it's for you. In other words, the benefit isn't for the forgiven, it's for the forgiver.
You say "You should not dwell on the past" and "You should move past thinking about past harms, but that does not require forgiveness." I disagree. In my view, that's what forgiveness is, in a certain sense.
You might be able to avoid thinking about the pain of the past, but unless you forgive, that pain is still buried deep somewhere inside you. You're just bottling up the emotions, and they find subconscious ways of seeping out into your moods, your perceptions, your behavior, your habits, and your interactions with others.
Forgiveness is when you pull that pain out by the root. It's when you remove the pea from under the mattress instead of merely stacking more cushions on it. It's taking the pebble out of your shoe.
"Getting over it" is a cope. It's what we tell ourselves when what we really mean is "don't think about it, pretend it's not there." Forgiveness isn't about merely coping, it's about healing.
You can still hold people accountable. You can still feel righteous indignation towards wrongdoers. Just don't make your personal happiness contingent on retribution.