There are many and complicated reasons why there continues to be a huge gap between the most wealthy countries and poorest.
These reasons include geography, technology, disease, colonial history, slavery and culture.
Each one contributing to the situation that the poorest country finds itself in.
In contrast Western Europe was blessed with favourable geography, leading to highly productive agriculture and food surpluses which allowed the wealth to be directed towards institutional and industrial development.
In contrast much of the developing countries geographical position meant that cash crops were more successfully grown which in turn was owned and controlled by the wealthy nations. The vast amount of mineral wealth in Africa is also largely owned by wealthy westerners.
The history of the developing nations which included colonialism, slavery and exploitation by the west have a continuing and direct effect on poverty.