Answer:
Most of the countries that gained independence after 1945 continue to be poor, or are at best, emerging developing countries.
There are some exceptions such as Singapore, Hong Kong (belongs to China but is semi-autonomous), Taiwan, Brunei, and Qatar, but the majority of these recently formed countries have a great degree of economic issues.
A combination of the consequences from colonialism, such as unfair exploitation of natural resources, and also, poor internal management from the domestic governments that came later, are the main reasons for this phenomenon.
