Doesn't help that most pax refuse to stow small items under the seat in front.
This is where a lot of cabin Crew have problems and it is really their job to enforce the requirements of their airline...
If a pax has said to me I'm not putting the bag on the floor under the seat in front of them and the lockers are full then I happily tell them I will arrange it to be loaded in the hold with the rest of the luggage.....
Sometimes you have to be forceful in a diplomatic way of course....
