The meaning and significance of the quote from Cry, the Beloved Country relates to the centrality of Johannesburg and its melting-pot characterization.
The quote begins chapter 9 and reinforces the primacy of Johannesburg—the biggest city in South Africa. For better or worse, Johannesburg is where the action is in the novel. The plot revolves around Johannesburg because Stephen Kumalo has to go there to check in on his sister Gertrude and locate his son Absalom. The quote is significant because each sentence ends in "Johannesburg," which alludes to—or references—how the destinies of the characters entwine with Johannesburg.
The quote is also significant because it relays the desperation and struggles experienced by many of the characters. Consider how the quote presents Johannesburg as an inevitable but unattractive destination. It’s not like people want to go there, but the lack of opportunities pushes them to the place.
Arguably, the quote captures the hardship felt by Gertrude and Absalom. To survive, Gertrude sells alcohol and appears to engage in sex work, while Absalom and two others rob and murder an activist. Johannesburg hosts these developments due to its chaotic and disparate elements.