Nairobi is full of apartments all over the poshy areas like Uppeerhill, Lavington, Kileleshwa, South B, South C, KilimaniWho said it is? Nairobi has them all over the place. The only difference is that in Nairobi, you'll never find apartments in posh estates while in Dar it's the epitome of poshness.
PLUS
Real estates development projects owned by companies like Runda, Tatu city
PLUS,
SLUMS where common Kenyans live.
And, those with little money, and don't want to live in Pipeline or othwr slums live all the way to RUIRU.
In Tanzania, appartments are not common. Its just a new thing for foregners and Airbnb.
In TZ we have no such a culture of residing in apartments, especially with a familiy.