This is objectively and manifestly false.
The African "countries" (there was a range of political systems to be clear) - particulary in the North and North East - had incredible economies that had rich histories, complex political structures and at least one of them (modern day Ethiopia) was the richest the world has ever seen.
The Europeans "came" as you put it, because of the wealth of these countries.
They were able to subjugate them because:
1) They had advanced weaponery (that they had stolen) to the African "countries"
2) They spent a couple of hundred years systemically and ruthlessly stripping most of Africa of its men, women and children who were captured and sold into slavery. I'm talking millions of people (~12.5m)
3) They brutally repressed any uprisings, including slaughtering thousands of people indiscriminately.
It is antediluvian to even suggest there weren't economies in Africa. One of the oldest civilisations in the world is in Africa - who had a complex system of government, an integrated economy and an engineering capability that has never been matched - I mean they built structures that are still standing 4000 years later.
Indeed Europeans adopted a number of the economic practices of the Egyptians. Just like we lifted a number of our mathematical structures from the Arabs of the Middle East, which is adjacent to the African continent.
It's not often that
@Magaoidh and I agree - but on this he is 100% correct. If we don't learn the lessons of history we are doomed to repeat them.
The middle east conflict is a prime example of this.