The only nation in Africa not to be conquered/colonized was Ethiopia. They even managed to defeat the Italians in a war. What made the Ethiopian state so resilient to European colonization?
Asking a question again is O.K. Mentioning a previous discussion is intended to be a starting point, not to discourage follow-on questions, data, or debate.
There's a section in the FAQ about Ethiopia. It has 5 links to applicable postings. The direct URL is https://www.reddit.com/r/AskHistorians/wiki/africa#wiki_ethiopia
In the app, unfortunately, # anchors don't work. To get to that section, search for East Africa / Ethiopia