I just come back from a return trip 30' ago. I paid attention at the demo while looking around with short glances what other pax where doing. I flew with the poshest (!) airline that fly the route...
My observation is that very few people look at it. What I don't remember is where the crew demonstrating looking at? TO the ceiling or the pax. It would be very useful if during the demo the crew were repeating "plese pay attention this is vital if" during the demo if/ when few pax were not paying attention.
Rwy in Sight