I currently spend ninety plus percent of my handgun training time with a red dot pistol. My carry pistols are about 50/50 iron sights and red dot.
At one point, I worried about getting “killed in the food court,” if caught with an iron sight pistol, and tried to devote more training time to iron sights. As I shoot more and more with a red dot, I have noticed something odd about iron sights. When I draw an iron sight pistol, without realizing it, I now shoot it like a red dot, using target focus. I feel like I am getting a significant amount of the red dot benefit shooting iron sights, especially at realistic defensive pistol distances. This was unanticipated, but it sure has simplified my pistol training.
I think the reason for this, is the red dot forces you to really refine your index, in a way that iron sights do not, since you can get away with much more misalignment with iron sights than with a red dot.