Okay I just read the new Sam Wilson issue and Sam's preaching about how Wakanda could have done something for their people all this time. Now that I think about it, its kind of a naïve statement to have all these expectations on this one country no matter how advanced to stop colonialism.
It also underestimates how nasty it can be. Britain wanted better trade deals with China but they refused so ya know what Britain did? They introduced opium into the country. The brought down the country by making its citizens addicted to drugs, it got so bad even the nobility and members of the royal family were hooked on the shit. It was absolutely despicable what Britain and thats just one country they battered in the name of their empire.
Then there's Japan they didn't wanna trade so the US sent gun boats to hold villages hostage and force them to trade. And then there's literally everything the US has done to collectively the entirety of South America.
Thats the thing, Wakanda could have helped but it would also mean painting the biggest target on their backs. You can't downplay the dangers of this shit, sure Wakanda is advanced as Hell but you don't need to wage open warfare on a country to bring it down. You just have to be a bit clever and having no moral standards to get what you want.