Earlier quoted context omitted.
Having a private room is not the same as living alone (having a private apartment/house). I think it's reasonable for young people to have flatmates and share an apartment, for example.
Its reasonable, but as we've advanced humanity in so many other fields (medical, technical, agricultural) why shouldn't the base standard of living also be increasing.
Theres also lots more people, and as more people consume more resources it does not follow that better technology in some field will translate to increased every aspect of life.