The problem with shared bathrooms & kitchens is that no single person is responsible for cleaning them and as a result they end up being messes. It can work (in theory), but in practice it ends up getting ruined by lazy jerks.
Dorm buildings are still thinner and have more access to natural light. No matter what you get these awkward units and dystopian unlit spaces internally. In places like nyc with huge, city block width apartments, there are actually internal voids that let in natural light deeper into the structure.