It's much worse for Africa than the EU. Here are the ratios of GDP per capita of the highest to lowest states in each region, excluding outliers DC and Luxembourg:
Africa (PPP): 50:1 (Equatorial Guinea $35,000 : Central African Republic $700)
CAR isn't even an outlier. There are several African countries with less than $1000 GDP(PPP) per capita and several with over $10,000. So it's much more diverse than the Eurozone.
US: 2:1 (Massachusetts $66,000 : Mississippi: $32,000)
Eurozone: 4:1 (Ireland $71,000 : Latvia $16,000)
Africa (PPP): 50:1 (Equatorial Guinea $35,000 : Central African Republic $700)
CAR isn't even an outlier. There are several African countries with less than $1000 GDP(PPP) per capita and several with over $10,000. So it's much more diverse than the Eurozone.