This only works if your country is self sufficient, from a resources standpoint and a IP standpoint. If you lack either, you participate in a global economy. And if you participate in a global economy, you need capital.
Say you’re the smart Kenyan who is willing to work. But there is no work in your country, or the only employment you can find is something that doesn’t use your intellect. You are that guy who can fix cars for a living, but there are no cars in the country. There are bicycles to be fixed, but they don’t pay enough to feed your family, or make progress.
You can choose to write essays, make money in dollars and afford a car. You can spend money in the local economy so that others can afford education, grow themselves and afford a car. Eventually you can create your own business locally to fix the cars. Or even better if you manage to make a lot of money, you can build a business that allows others to build their own business.
Or you could continue fixing bicycles, make no money and constantly worry about survival, and never do anything more than fixing bicycles.
And this is how capital and modern economics works. I’m also from one of those places. :)