At 20K a year it would seem African developers would be a competitive outsourcing option for wealthier nations. Is there a reason they're not a well known name

At 20K a year it would seem African developers would be a competitive outsourcing option for wealthier nations. Is there a reason they're not a well known name in outsourcing? I'm guessing it might have something to do with infrastructure, when countries like India and China can compete at these prices but have the infrastructure to support working remotely.