@FreeBritnee
Because he didn’t want to house share anymore. That’s the compromise he has made for his own space.
Just wanted to add "in london." In the majority of the UK you can get get a significantly larger amount of your own space for £900. I have a 2 bed semi for a mortgage of £300p/m in a different UK capital city.
If you are a single person without a family, the vast majority of jobs can be done outside of London so it is to some extent a choice to stay there and pay extortionate money for a tiny space.
I don't think there's anything wrong with a very small bedroom and bathroom. I had an absolutely tiny room with ensuite- much smaller than 37m and it was fine, but I had a shared kitchen. The problem comes when you need to add cooking and food storage and preparation facilities and I can't see how people can get around the issue of fitting small flats with then.
I really don't understand why we consider it essential to fit at least a washing machine and often a tumble dryer into every flat though. Elsewhere in Europe and the States most flats have a laundry room in the building for shared use. No idea why we don't do the same! It must be healthier than having washing drying in such a tiny space and when i lived alone i barely did one wash a week anyway so seems a bit of a waste.