Well, im the 3rd largest african airline. And i can give ya some hints coming from there.
Africa generaly dosent have that many competitors in it. Now its home to about 30, 10 of which are serious. The problem with africa is there are just two few good airports. There are only 3 airpots that have above 10million passengers, and only 7 above 5 million. In total theres about 15 airports total that are even worthy of putting a hub on on the entire continent. That sounds all fine and dandy but dosent leave much room for growth. Your garenteed to run into competition with atleast 3 other people at an airport that serves 2.5million people flying rapidly devalueing routes to airports serving 100k people or less with newbs running 5 frequencies on Beech99s.
By the end of the game, pretty much everyone is in everyone else hub. And the competition can get nasty, especially on the mediteranian cost. Early on you can find a nieche, but it will be taken from you 3 years in or sooner. Mediteranian airports are the most lucrative for a brief period, till two other people build hubs there, and european airline dump there A300s on em.
And though South Africa looks like a good country to start in, youll be needing an expensive long haul fleet within a year, since outside of that country theres vast expanses of nothing. And once again, every newb that comes to africa decides they need a hub down there. Pretty much every major airline has a base down there, clawing at a piece of that ever so lucrative {not} Johannesburg/Maputo route.
As such i declare Africa and advanced continent. its not very friendly to start in, and less friendly to compete in. Especialy if you open a hub in my city, that tends to make me cranky.