Look at the size of the country (around 1/3 of USA) and the number of people living there (112M according to wikipedia), also 1/3 of USA. So the density should be about the same but when you look at satellite photos it's one giant city (18M), several smaller cities and the endless forest. Can it support other 90M people?
So yea, DRC can easily be like that. Especially if they don't subscribe to 4-6 people living in a house thing that the US does.