I did try asking some locals in my office to lunch at 11:30 and they looked at me like I had three ears. Of course, they usually mosey into the office around 9:30 and slurp noodles until 10:00, so I can see where they might not be hungry at 11:30.
In my office, they don't care if lunch takes 2 hours due to congestion. In fact, I think they prefer it that way.
The issue isn't timing of lunch, people riding up when they are going down, etc. It's that the elevators are small. In NYC people manage to live and work in high rises without there being so much chaos. Never heard of staggered lunchtimes there. Buildings in HK are designed for profit maximization, squeeze in as many flats/offices/units and keep the elevators as narrow as possible.
You might be right about the undersized elevators in some elevators. But it could also be over populated offices. Same overall problem though...greedy property developers and high rental prices.
I've seen worse in Beijing and Shenzhen...Lines 50+ meters long, every morning to get on the lifts. Crazy.
Luckily my office is on the 6th floor, I always take the stairs its heather and theres never a wait. At home I never have to wait much more than 30 seconds.