It seems that the rich black soil in the Amazon was man-made and has lasted thousands of years:
But note that this is not all or most of the soil in the Amazon, by a long shot... the "terra preta da Amazonia" exists in isolated patches where humans had been conducting slash-and-burn agriculture for hundreds of years. Most of the soil of the Amazon region is just like any other topical soil, nutrient and carbon poor.
Upshot: if you are a young scientist/engineer/agronomist/ag economist and want to do real hands-on exploratory science where everybody is in the dumb club, and still make a significant direct middle/long-term difference in the world and its population, soil science could be your ticket.
PS: The content of the article is great. The click-bait title is absurd.