To me, the biggest "feature" which I never would have expected to miss is the inability to immediately retry a battle. I remember being very excited when I learned that some games had a soft reset by holding the shoulder buttons while pressing start + select. It would make sense that cutting out this process entirely should make me happy.
I don't think anything breaks my immersion, sense of accomplishment, or desire to do better quite like unlimited, instant retries. I died ~187 times in The Last of Us on normal. The game claims I beat it. In my head, I feel like the ending I EARNED involves Joel being dragged away in the grill of a truck. The same for FF13. I beat it, we're heroes Snow! HEROES! Nothing can stop us! Noth- oh crap I got one-shot by a behemoth again, retry - NOTHING! HEROES!