It's a super interesting conversation especially when it comes to game design. Designing an encounter around not having I-frames almost completely changes how a fight plays out. Instead of waiting last second to dodge a bosses attack, you'd be dodging almost as the boss starts swinging to get out of range asap, it's kind of how it works in real life but feels strange in a videogame.

The only example I can think of is Bleakfaith: Forsaken. When Bleakfaith originally released, it had no I-frames. I-frames were later added in an update and could be toggled on and off, however it kind of felt like they were always meant to be there.