The desire to undo things done must be as old as civilisation itself. People say and do things they wish they could take back. Undoing history would be lovely in some respects. However, there is no giant red rewind button to facilitate this.
Wouldn’t it be nice if such and such had happened or hadn’t happened. The musings of those not wanting to accept the brutal facts of reality. Things are as they are today. They are like this precisely because billions of people did trillions of things and they can’t all be undone.
By constantly living in the hope of the past being different, we can drive ourself to madness.
It may give us some comfort to hope that we will be young again. Or even that wars will not have been fought and past transgressions never occurred. Spending time on trying to right the past uses up energy we could use to improve the present and the future.
Sure it would be better if certain things were a certain way today. Anyone whose family has had a difficult past would probably agree. However, it has happened a certain way and we must make the best of it now.
Rewriting history might make you feel better about the story but the results are in.
Undoing history is still not possible. Best to focus on what is.