The Mali Empire was NEVER prosperous - just individuals like Mansa Musa and his appointed cronies. And vastly influenced and helped onto their feet by the
ARABS. The average African in Mali was poor and uneducated as dirt, just as today. And again one does not provide for a prosperous economy and society by simply selling of raw minerals and natural recources such as salt and gold.
A prosperous economy beholds foremost an INDUSTRY and Trade- like those in Flanders in the 14th century - producing woven textiles and naming their richest city in Europe GELDERN = aka MONEY.
As for being the richest person in the world - this infantile article doesn't provide a single fact or proof towards his wealth. No bookkeeping records - NOTHING - except FABLE - fabulously wealthy.
Ever hear of a guy called
Jacob Fugger the Rich? in the 15th century - proven via BOOKKEEPING records. !!!! And that was an INDIVIDUAL business person and not some despotic King or Emperor robbing his country and it's people of their money and livelihood.
This man beats every other rich person on the planet, with a net worth of around 400 billion in today's dollars.
biographics.org
But I don't expect an African like you to understand and know this.