Part of the thing is that Luke/Leia/Han are no longer the central heroes. So expecting them to show us these big events in their lives is expecting a different approach entirely. They are no longer the focus.
Plus, part of the idea here is starting at the lowest point (or near close to it) and finding the hope and fighting forward for the light from there.
I agree with you, but starting at the lowest point with a new hope is literally the plot of the OT, and we’ve already seen it.
No, it is the premise of the OT in simply the vaguest of definitions.