I don't understand, do you mean that the concept of Africa has a basis other than it being a landmass co-inhabited by groups of people?
I don't see how there are any relations between a Zulu and a Somali. We just happen to share a contiguous landmass.
that's not really what i mean. i'll try to explain it a little better and i'll use the whole eurasian mota fiasco as an example. essentially an ethiopian man dated 4,500 years ago was found with his DNA intact. originally it was postulated that there was a gigantic eurasian migration like 4,000 years ago for sub-saharan africa because Mota (the genome they found) did not possess the eurasian genetics they found within other Africans. basically it was an oversight and they realized a good chunk of that genetic material was always in Africa, and that it was taken directly from East Africa (but there was still a Eurasian expansion for the rest of the Horn).
this is statistically relevant because you have two originally unconnected areas being the confusion for an entire species. to put all that into perspective, because of the sheer fact that life originated here and dispersed throughout the continent before it reached other areas, the connotation of African is perhaps the only relevant continental monicker when we discuss exactly where we came from, and could be the clue into explaining everything from migration to language evolution over time.
so essentially you need to look beyond the lens of merely a group within the continent, and assess its significance as a whole. which is why the term isn't insignificant but perhaps the only real significant term until we can definitely explain everything about our history. the hilarious part is how the key to humanity is locked within the most ethnically diverse continent on the planet.
beyond that you have minute similarities like how impoverished the entire region is, the mutual history of being colonized (however there are differences even there), trade and now a continental union that is still in its infancy. so Africa went from being a completely baseless and unimportant monicker for just the North, to being the only continent with gaining relevancy in the new age. it's a purely 20th and 21st century product, but the relevancy lies therein.
so the point is bascially that it is relevant but not at all in the same way that europe or asia is relevant, and it has virtually no similarities to how they operate. it's a completely unique term and the only one with an entrenched disposition within the sciences (for now).