Things change, for sure. To say things change is probably an understatement... Just look at the history of the Middle East. From vast, wealthy empires to barren destruction, the Levant has seen it all.
True but people and nations have more agency than people give them credit for. Finland was invaded and at the mercy of imperial Russia, they also were under Swedish control, etc. in other words subject to imperialism. They suffered famines in the XX cent., not too long ago.
People think, oh, imperialists messed with you, no wonder you’re poor!
No, it’s local mismanagement. Look at Panama. From banana republic to a democratic republic. People have to work for it. Their government has to be more honest than not. Eliminate corruption as much as possible.
Conversely look at San Francisco. So much money and so much corruption and waste. A decent government and it would be such a better place for everyone, including the poor.
When I think of imperialism I often see the exact opposite. A more advanced society is (often violently) forcing modern customs upon the invaded population and when the imperialists leave a lot of those modern customs get lost and the country turns into a backwater again. The imperialists might be evil, but they clearly knew what they were doing.