Let put some perspective around this. That could be 2 metres wide and 4 metres long. Did he rent a bedroom and share a living area with others?
He has been living in Amsterdam for almost two years now, if you're young, don't want to spend a lot of money and you want to live in "de ring" (the inner city) it's your only option.
It's perfectly livable though!
Instead, it is 3 people living in ~40 sq M.
I did the same thing when I first moveD to Boston. I got a bedroom in a four bedroom one bath townhouse, and the rent was quite reasonable split four ways. The shared kitchen and bath were not a problem, and I had plenty of space for one person with just a bed, desk, and dresser.
Now I pay more than that entire place for a 60 sq M place for my wife and me, that is only a 15 minute bike ride from work.
Ha, try living in The Netherlands!
I live in 24sq meters in a reasonable large city, my brother lives in 8sq meters in Amsterdam. We pay about the same and really, given how much the city offers neither of us complains. We both have a 5-10 minute commute by bike.
I have all the stuff I need and very little of the stuff that I don't need. We both live pretty close to a park, I can rent a place in a coworking space for 100 euros/month (including unlimited good coffee!) and given that I do things outside of the house most evenings anyway this works out perfect.
I couldn't imagine sharing my place with someone else but then again a friend of mine is living together with his GF on 28sq meters and they rarely complain about lack of space.