Imperialism not only helped modernize South Africa (which was the longest colony held by Europeans) but majorly increased their economic system. Countries such as the former Rhodesia and South Africa both were the longest colonized by Europeans and both thrived economically. Rhodesia declared independence from Europe in 1970 and was controlled by Europeans through 1978.
And even though their existence was short, they managed to maintain one of the strongest economies in the world. They were so strong that $1 Rhodesian= $1.40 American, making it worth more than the Euro and the American dollar. It's society was also very modern and had multiple media sources and news papers, also a modern army. But in 1979 and 1980 when the country was completely lost from European control the economy crashed. They were so inflated that they were printing out $100 trillion dollar bills. Then the Aids epidemic spread across the country and they did not have the education or technology to control it as the former European government did.
Also another example is South Africa when Europeans lost complete control over the country. Crime shot up an incredible amount and AID's ran rampant just as it did in Rhodesia. And there was no way of stopping it because even the government would issue false propaganda that only made Aid's even worse.
No. Imperialism should never be regarded as something that could have improved the world, or ended extreme poverty. Imperialism is the reason for oppression, and even if a conquered people were comfortably assimilated into the culture of their oppressors, those people still view their situation as being oppressed. This is never a means to improve the world.