Sadly, Hong Kong can be way worse than these already super-cramped one-room apartments.

The apartments in your link are either tiny 1960s social housing, or subdivided apartments. With the ever-increasing rent, some of these have since then been subdivided further into single beds (a.k.a 'cages' or 'coffins', depending on how they're sealed):

https://www.theguardian.com/cities/gallery/2017/jun/07/boxed...

Yeah. I raised in a similar place. And now I'm sitting on my bed to write this comment. And my bedroom about 3.6m^2. It's also my working space :)

(my apartment around 250 sqft. I'm living with my parents)