I wonder what has happened to the old adage of using the space under the seat in front of you. Certainly most travellers are reluctant these days to exploit that space even when there isn’t any room left in the overhead lockers. There could be an argument for using that under-seat space to accommodate valuables (e.g. passports, wallets, credit cards) in a small soft bag/handbag that could be safely put in a pocket (or somewhere similar about the person) in event of requiring to exit in an emergency.
On a separate point, it is interesting to contrast the typical aircraft safety briefing with the process that is compulsory before a cruise ship leaves harbour. Passengers that don’t register at those briefings will not be allowed to continue on the cruise. I wouldn’t for a moment advocate that the same process is followed for flights, but something perhaps could be done to penalise those that choose to ignore the briefing, especially the bit about leaving belongings in the overhead lockers. As a frequent flyer on different airlines I am also very much aware of the different fastenings for lifejackets (e.g. clasp vs double knot) and always want to check which variant is provided on my flight.
I agree that more could be done to make the briefing more watchable, without detracting from its purpose. BA’s current offering is very dated (as already pointed out) and really needs to be refreshed. In comparison, the Air New Zealand briefing is always very watchable, memorable (especially for those that normally couldn’t be bothered to watch) and refreshed on a frequent basis.