You are forgetting the lighting factor.
A scope can make a huge difference in very low light and I've often had to pass up shots when using open sights that could have been taken with a scope.
I much prefer to hunt with open sights but like to have a QD scope ready in case the lighting is too poor for the irons.
Much hunting for big boar pigs in outback OZ is done at first and last light as they are mainly nocturnal and having the option of being able to use irons when possible as the main sighting but also have a scope ready to go on if needed is the way I do it.