Things being Swingy means to me that characters do not become invincible; many Retroclones are built from versions of D&D where you can't end up with a character hith more than 50-75 hp (and frequently a lot less- some have max hp below 40, and the OSR informed game I play, GURPS Dungeon Fantasy, has Max HP for the toughest humans at 30 and the largest barbarian ogre at 45). While dying is the least interesting thing that can happen, immortality is the next least interesting thing. If you always choose to fight instead of parley, sneak, or run then you will die. It may take a while, you may have exciting adventures, but sometimes you will encounter situations or opponents that are out of your league, or you may make a bad decision, like trying to jump a pit, or climbing without a rope, or pulling the wrong lever. Recognizing the risk can make decisions more thoughtful, and dying to save someone else, or out of catastrophic failures can be the stuff of stories told for years afterward. I know my group commemorates some of the wordt PC deaths, and we joke about some if the mishaps that lead to PC deaths over thirty years ago to this day.