I really am at a loss as to what one might take in a carryon bag (allowed by TSA) that would help them to survive a commercial plane crash. When a plane crashes, one survives or they do not. One might increase their odds of survival by selecting certain seats based upon odds, but that is iffy at best.
If the plane did crash, and you did happen to be one that survived the crash, you would want to get out as soon as possible. I cannot imagine delaying exit long enough to locate a carryon bag, then exiting the plane with it.
Since staying in the vicinity of the crash would greatly increase your odds of rescue, you would have the opportunity to pick thru the wreckage for useful items. Food from the galley, medical supplies, the axe in the flight deck, cushions, pillows and blankets, contents of others' baggage and even pockets.