Personal Responsibility
 

Not sure there's many companies still around that offer unlimited liability in today's litigious climate. Airlines have upper limits to their liabilities in their Ts & Cs of carriage.
There is a provision to increase their liability when checking in. It's called (as I recall)"Excess Valuation" and covers the difference of what the carrier's liability is and what "you" say the value of "your" item is.
2 issues
1) getting someone at the airline who knows what to do in this case and
2) proving the value to the airline's insurers.
Any sensible person will have taken personal responsibility seriously and will have taken out their own all risks / home insurance policy for their valuables.

International (and all intra-EU) flights are protected by the Montreal Convention 1999 (MC99) which limits an airline's liability for loss or damage to about SDR1300 per passenger. This is the extent of airline liability, unless you can prove that they did so intentionally.

While, in theory, you can get Excess Valuation - find me an airline employee that has any idea what you are talking about, I'll give you a free beer.

It isn't just the airlines, it is also the (pax's) insurers who insist valuables must go in carry-on. Flights out of the UK did in fact go through a brief period of "everything in the hold" at the beginning of the liquid-ban - it was a fiasco. A lot of people lost valuables and were then passed back and forth between airline and insurer with each saying it was the other that was liable.

It is this lack of a joined-up approach that leads pax to distrust the whole industry/system and thence to grab their own stuff. As another example of this, Trump recently banned some devices (laptops, but also cameras) from cabin baggage while at the same time the FAA appears to have been working on (and still is I think) proposals to ban the same devices from checked baggage (and cargo too?). How does a camera crew actually fly then? Who in the industry is actually looking at the whole picture and standing up and saying "this doesn't work"?

I rely on medication to stay alive these days, and it won't fit in pockets (well, actually I could fit a weeks worth of pills in a large coat pocket, but I am not allowed to because various rules (non-joined up approach again) in numerous places require me to carry medication "in original packaging" - which is too big). I would happily hand over / check-in / leave my meds if I believed and trusted that the industry/system would replace them if I don't get them back at the end of the journey, but I don't (and with reason). Until that changes, my meds are in a bag that I can easily and quickly grab on evac (which will be bigger that it might be because it has to have other stuff that I could leave behind, because... only one bag allowed, sigh).

Or even more exact, your camera and precious phone is worth killing somebody...

TSB Report now out