Economic numbers are far less important than other contributions.
Where is space agency of Africa, how many satellites it has launched, any significant contributions.
Secondly, India's GDP is vastly undervalued wrt. Africa or China.
A price comparison between Nigeria's capital, Delhi and Beijing is as follows:
www.numbeo.com
Everything is 50-60 % more expensive in China, be it milk, bread, school fees.
Africa is also more expensive than India. Here is Delhi vs Abuja (Nigeria capital):
www.numbeo.com
African prices are also 50-60% higher than India.
Indians earn less, but are forced to spend lesser. This difference is well accounted in GDP (PPP):
Where India is 10.1 trillion, China is 24 and Africa is 6.9.
There is no comparison between India and Africa on GDP (PPP) per capita. It is 50-60% higher and if you remove South Africa and rich nations like Egypt, it will be 2-3x below.
And that too, despite having 50x more oil than India and far more natural resources and a much bigger continent.