A Canadian runs 21 pages dedicated to African countries on Reddit

You are missing the point, which is that part of the problem for low participation, as experienced with r/Eritrea, is that hate speech is allowed and other anti-government messages banned which drives users away. Add to that the moderator doesn't und

In fact reddit unpopular in many African countries. Facebook group is mostly common. E.g. in r/Eritrea cases, there are large community of 30k in facebook, but r/Eritrea is also run by the Canadian reddit mogul.