Egypt is also a useful case study, because the US props up its shitty government. That's also part of how the Global South is underdeveloped, it's a multifaceted machine that sucks out everyone who can help make the country better and gives support and resources to the people making it worse. It's not just legacy from the 20's and 50's, this is an ongoing problem that is created by imperialism.

Also when a Global South government tries to solve its problems, such as through nationalizing resources or land reform, the US buries them under sanctions and attempts to make a regime change. This, too, is part of how imperialism underdevelops the Global South.