Tightslot, I sense a challenge above!
As credentials; I've been in the industry for 38 years, including time standing in as a cabin attendant in the days before training and qualifications became desirable. I've worked at most levels in most parts of an airline, including managing a start-up. I imagine I must have heard the safety briefing once every 2 weeks or so on average in that time, ie fewer times than professional crew but more often than many. I've been involved - as a passenger - in a runway over-run on landing, two hijacks, and several lesser emergencies such as engine failure on take-off etc, and observed how people react in these situations. (Which is why I don't have much time for the evacuation time tests carried out by manufacturers).
The requirement is based on the fact that no-one dares to say, about any safety-related practice, that it's time to drop it. We add rules all the time, but very few if any are dropped when they reach the end of their usefulness.
The briefing was introduced when flying was a rare event for most, many passengers on any sector were on their first flight, and aircraft were markedly different in their design, safety feature and escape routes.
These days none of that applies. Most importantly 99% of everyone on board has heard the briefing several times in the last 2-3 years, and of them many could recite it in their sleep.
The result is that those people ignore it totally, with the result that if there is an emergency and they are required to act quickly and decisively to save their lives, and the lives of others by doing so, they probably won't because they have to think first about what they can recall.
A better way must therefore be found, based on the knowledge that all, or very nearly all the passengers are aware of the exits, how to put on a lifejacket and when to inflate it, the underfloor lighting, how to fasten a seat belt, the need to put the tray up, and to have the seat upright (not a problem on Ryanair, of course). We can also count on a number of very experienced passengers in any cabin.
Everyone is also aware that aircraft can and do have accidents, although very rarely. There's no need to use patronising and silly expressions like "in the unlikely event of....". Passengers are not stupid; some may have flown more often than the more junior of the cabin crew.
My solution is therefore an announcement such as "If we experience an accident, you will need to immediately take the appropriate action, under guidance from the cabin crew. To do this, you must be aware of all the safety features and what to do in an emergency, which are described on the card in the seat pocket. Careful study of this may save your life".
However, we need some facts. To get them we should test verbally 1:10 passengers - selected randomly, regardless of age or language - on their instant recall of what to do in an emergency, which exit to go for, how etc. Also ask them to "don" a lifejacket, while remaining in the seat. Time allowed 30 secs. The test should be carried out during the descent. This survey should be done on 100 flights where the safety briefing is run as normal, 100 where no annoncement whatsoever is made, and 100 where the announcement is something like my suggestion (with improved cards!).
Any airline brave enough to take up the challenge?
It's not the announcement per se I'm against. It's the fact that it's so ineffective.
PS I'll own up re the lifejacket test...we tried that once, years ago. Success rate (ie on correctly within the time limit) about 4%. 13% of the LJs were inflated, some because that's what the wearer thought he/she should do, the others accidentally.