If I'm not much mistaken, this is no longer the 1930s where travellers go around in (relatively) slow and light propeller driven aircraft which, if forced to do an emergency landing, put down in the jungle somewhere where the occupants find themselves befriended by a tribe of gorillas and then go on to to discover overgrown ruins with gold aplenty and natives with bones in their noses who they have to fight with before emerging alive and well in Cairo.
No.
In the 21st century, if you were on a holiday flight that had an emergency, you would either be dead when it hits the sea or, if it did manage to do an emergency landing, it would likely be at an airport since there are many more of them now than their used to be, so you would be better off with a mobile phone (so you can call family and let them know you're OK) and your credit card (so you can buy the things you are going to need).
A tobacco tin with a length of paracord, a few plasters, a whistle, and what not would be useless and pointless in this situation. I think you've been watching too many Ed Stafford TV programmes and taking them seriously.
Statistically you are probably safer on the plane than you are in the taxi to or from the airport or in your own home so other than water, wet wipes/hand gel, small FAK with immodium in it and a torch should see you right in most of the scenarios that are likely to happen as well as those that won't.
True.
There is nothing wrong with taking a small FAK, key chain torch (these are about a tenner, and very bright -
https://olightworld.com/store/flashlight/i3e-e0s-black.html), something to drink (small bottle only), painkillers/imodium and earplugs, plus a book - thats the sort of thing you need just to get through the airport! But pretty much anything else is pointless, even if your allowed it in carry on. I would possibly add a small kit for shaving, washing, etc, just in case they do lose your luggage, but since they tend to take shaving foam and razors off you, I'm not sure I'd bother. Just take lots of money, because thats what you'll need at any airport, if only for a coffee.
Best thing is to know what to do if your in a crash, evacuation, etc. Count the steps you need to take to get from your seat to the emergency exit, because you might be doing that in the dark with smoke, and know where the life jacket etc is, and
not what to do with it (inflate), as well as how to put it on, and how to brace for a crash. And wear shoes that are comfortable for the trip, and will be easy to move in.
I do remember years back reading a book published in the early fifties about air travel, and a stewardess tried to stow a package a passenger was holding tightly. It turned out that the passenger had decided to bring her own parachute!