>>512354685Because you can't take tribals with no written word, dump them in a first world city and expect them to function on the same tier as the people who have spend thousands of years cultivating that civilization.
They need to go through developmental milestones at their own pace, with guidance. Each tribe had their own homeland where they were free to make their own laws and issue their own currency.
My grandfather told me a story about how they set up an agricultural/irrigation project in one of the homelands. They had a record maize harvest. The next year when they came back they asked them how this year's crop was doing. They answered that they still have corn from last year so they didn't need to plant more.