I guess you haven't had that BA brief or it's successor inflicted on you several times a month/week/day...........................
It works really well and grabs attention if you haven't seen it before..however it does start to grate after you've seen it a few times, and not just with the passengers...
I think crew opinion is it is too long winded, causing delays in getting the cabin ready on short taxi-outs....a real short haul bugbear
It also doesn't work so well on a lot of Longhaul routes, especially those where the majority of passengers don't have English as a first language, don't know who the "celebs" are, and don't get some of the humour ..even Mr Bean isn't unversally understood or appreciated.
Keep it simple, keep it short...save the entertainment stuff for once airborne..
That said, I always found this safety video easy to watch: