The term “banana republic” was invented for latin american countries, where companies like Chiqita had a ridiculous amount of political power, because they were the sole driving force behind the entire country’s economy. These companies (often banana, but could be any resource) had so much power that they pocketed and corrupted the entire system. They removed farmers, forests, civilians, politicians, competition, villages, anything that stood in their way, they just moved it out of their way, the easy way or the easier way. They could do whatever they wanted, because they pretty much were the government. (Fun fact: This led to massive monocultures and the virtual extinction of the Gros Michel banana)

It originaly applied to latin american countries, but it can apply anywere. It also doesn’t have to be one particular company who controls the government, it can be a bunch of them.