This is getting to be an old thread and there seems to be general agreement that in all cases it is situation dependent. However, I'm going to throw a differing ball into court and disagree with some of the views based on personal experience. Somebody asked for potential situation where a PSK is of use/real need, so:
Where you really need a PSK/FAK is in dense urban connurbations prone to violence and theft, e.g. London, but there are others, and you are a long way from home. Especially if you have grey in your hair.
I used to work in inner London, an hour-half by public transport from home. A Lofty Tin doesn't cut it. (I do have one, from the eighties when I did camping/DoE courses)
This is not necessarily the same as a Get Home Bag, but very close. A phone is only of use while you still have it, ditto a wallet with money/cards in it. Handbags & Get Home bags may be stolen at random (or forgetfully left behind on the transport. Lost Property have lots.).
Plastic cards can effectively be used to stop a sucking stab wound but something better might be needed to stop bleeding out. Do not rely upon help from strangers, or an ambulance or police arriving quickly, even in ordinary quieter towns. (The Zombie knife laws were due to the indent level, often random/rage attacks e.g. 3 guys died sitting in a park in the afternoon in central Reading stabbed by a PTSD crazed migrant, similar one, a couple of years earlier, several seriously injured, Reading again.)
Transport systems can and do break down or get cancelled, leaving you in difficult situations. (This has happened to me numerous times). Is that a survival/PSK scenario, mmm, situation dependent, you can make bad decisions, especially if cold or hungry. (Woody Girl & Disabled Prepper will be familiar with this situation).
A friend of mine spent 11 hours in a hospital this week, waiting to be seen, unable to walk far or drive, he was pretty screwed getting home late at night, and that was only 2 miles tops. Whenever I go to hospital A&E, I take food and drink, warm clothes and a book with me. And small change cash.
A form of PSK/Get Home with some form of food has proved useful quite often. I slept in a bin store once till daylight. If you are tired, got off at the wrong stop/transport breakdown and are lost, or get turned around and lose your bearings. A compass is quite useful in built up areas and estates that all look the same, (especially after a night out, even sober). A torch is good, saves getting hurt, (Falling/walking into things, including fists) , phones run out of charge quite easily and carrying a powerbank is not PSK. Not everybody accepts cards, especially taxis and minicabs, although that is changing. Locally, on buses you need their own "Oyster card" or similar, nothing else accepted. As you get older it's easier to forget routes, and again a compass sometimes helps.-, but having a drink of water/electrolyte helps even more.
Out in the Countyside, getting seperated from your rucksack is much less likely, theft is possible but not common enough to warrant much consideration. I guess most folk do not go fording streams or rivers, where they might unhook their ruck for safety in case they fall? Or have it too close to the fire? Or fall into a ditch or gulley/slope and need to signal for help? Getting to a road is not the end of it, you may have to walk miles afterwards, possibly in the dark,icy roads, in wind/rain.
Consider also, the two experienced lady climbers recently. Stuck on a mountain ledge because they relied on a single rope to bring up all their gear in a single rucksack. Why they did not each have a small climbing appropriate PSK on them is beyond me, pocketable or bum bag. No kit, no sat com, and a dying mobile phone that got one call out. That saved them, but it took 3 days to find them, they thought they were going to die.
So there are some scenarios, with no bears, but ugly delinquent youths. Not sure which is worse...
