This article is a bit ignorant, typically one provides just a rough area and a phone number so the courier can call and drop it off to you at home or at work.
This is why you just need a suburb or area and your cell #. You need to be available to sign for packages in African countries and they typically cannot just be dropped off on the porch.
The problem with buying online is just the availability of things is poor, you don't have an Amazon-esque level of availability & websites that do basically buy from Amazon and sell it to you after an extenuating long timeframe.
Ordering from abroad is a hassle because of customs and duties and ridiculous charges such as the SGR levy (for Uganda and Kenya) because of the new rail line (even though the rail line isn't really used for your package). If you order something small like shampoo its likely to cost triple and a minimum of $30 from abroad.
The only great experience I've seen is from takealot. Jumia not so much. Kudos to those guys who run Takealot.
For someone who has lived in Africa the address system, or lack thereof is just something people are used to - it's still possible to find places without an exact numerically marked address. It's likely a dedicated courier who is very knowledgeable on the local areas & landmarks is to drop the package over a postman so it makes little difference.
It's a bit of a shame when these type of articles come up once in a while that distill a "sort of issue" into the prime issue on why it doesn't work. It's not to say proper addresses would help alot, but it's certainly not the reason e-commerce hasn't really taken off. The last time it was a discovery on how a small fan can get rid of mosquitoes - obviously not the reality either.