Are they like that in captivity and the wild though?
Yeah, interbirth intervals are long in the wild as well. The situation there is compounded by the poaching and the bushmeat crisis and civil wars. Estimates for the entire bonobo population in Congo (formerly Zaire) have gone from around 50,000 in the early 90' to less than 5,000 now after the wars!

You take all the great apes together (chimps, gorillas, orang-utans and bonobos) in the world, you could easily fit them in a football stadium.

In captivity, the situation is also bad because the world zoo population of bonobos is around 200 - that's not nearly enough to maintain a sufficient genetic diversity beyond 3 generations even though individuals are exchanged among zoos according to carefully planned studbook procedures in order to keep the captive population viable for as long as possible.