Do they need to add vaping?
We call you yanks 
Pip pip, old bean!
Cheerio.
raises pint
I’ve learned to live with them; heck, I’ve flown so much I can probably do the briefing myself if called upon. That said, as others have before, it is for legal and regulatory reasons we get the spiel, and I don’t see that changing as long as we have bureaucrats and lawyers (which means forever).
Still, some airlines are creative in their presentation, especially those that use film (usually on more modern planes with individual screens). Without a doubt my favorite one is this from Air New Zealand: An Unexpected Briefing #AirNZSafetyVideo - YouTube
“Fly, you fools!” 
How very painful that must have been for Newton.
IIRC the smoking in restroom message and tampering with smoke detector message were added when someone did both - and caused a fire. Addicts are addicts.
Southwest also has amusing messages at times, depending on the crew. My objection to seat belt messages is that they might cause people to zone out and miss the important stuff.
And I don’t recall them telling us how to remove the belts, but I might have zoned out by then.
The standard shoulder-and-lap belt, as used in most modern cars, is a pain in the . . .
. . . armpit.
If I wear it over the shoulder (like you’re 'sposed to) it lands right on my neck and strangles me. So I put it under my armpit. Actually, it’s comfortable enough, but I’m pretty sure we’re not supposed to do that.
I really prefer the four-point harness of which Broomstick writes, as commonly seen in small aircraft, private planes, gliders, etc. They really go over the shoulders, not the neck. (I’d rather be flying anyway.)
And, for a few extra bucks, you can get them for your car! I just might do that.
Link, with photo showing what a four-point harness looks like. TL;DR: There are four belts: the two-part lap belt like in older cars, and two shoulder straps, one coming down over each shoulder, straight down to the lap buckle.
I believe the cabin crew use 4 point harnesses on rearward facing seats. For no good reason, I get a bit scared in planes and think I would prefer to sit like the cabin crew.
I can’t find stats on the relative survival rate of cabin crew vs passengers but I also read
that it is better to sit in the back of the plane, and within 5 rows of an exit. I shall ask for a seat in the last five rows next time I am given the choice.
So when the plane nosedives into a six-foot crater of its own making, you’ll be one of the last to go.
So that you have a twenty percent better chance of surviving a crash (67% vs 49%) than those at the front in business class.
I know how to use seatbelts in aircraft. They’re not much different from the seatbelts I remember in my Dad’s 1962 Mercury. Insert one end into the other, and push until you hear a “click.” Pull the slack end to tighten. Lift the flap to open. Easy-peasy!
Not only do I know how to use an airplane seat belt, I know how to use their extender seat belt (which I usually need now since I’m a, uh, fairly big guy).
Their extender is this loose thing, totally separate from the seat, that they hand you with a “receiver” part and “entering” part, that you use to clip the “entering” part into the seats usual “receiver” part and the extenders “receiver” part into the seats usual “entering” part.
It’s obviously not rocket science, but it does entail a few extra steps.
ETA: Here’s what one looks like.
All planes have them and all you have to do is ask for one if you want one as soon as you board…but since most people don’t need one, I’m guessing most people don’t know all planes have a few of them for their “bigger” passengers.
I never knew. I wonder if there, or could be, a product that clips onto the plane seat belt , and or perhaps seat, providing more support.
Yes, there is such a product, but only it seems for children.
Further, the reason why such products are only for children of weight up to 20Kg is because if large persons used such a product, being attached to the seat, it would cause the seat to bend forward in a crash, which would negatively effect the brace position of the person attempting to put their head on the back of your seat behind you. Hence, the FAA will not approve such products for adults.
From the FAQ
"The reason for the height and weight restrictions is the FAA’s concern that with a heavier traveler strapped to a seat back the seat would tilt forward more quickly in a short stop, causing the person sitting behind the seat not to be able to brace himself.
Airplane seat backs are designed to “give” when pressure is applied with bracing. This is important for the safety of the person sitting behind you. The FAA placed the height and weight restrictions to make sure that all passengers would be covered in the event of an emergency."
Also I did not know that a brace position required that I push myself into the seat before me to the point that “gives” but I guess in the event of a crash I would be so stressed out I would be doing this and I guess it stands to reason.