The true story is bigger than Bezos or any other digital 'robber barons'. Income inequality ebbs and flows, controlled by many complex factors like public policy, availability of labor, etc. In the US, this tends to follow a 50 year cycle. For instance, from the Great Depression to 1980 was, like you said, our last cycle of decreasing income inequality. During these periods, the US is governed by a vigilant generation that is aware of the consequences of income inequality, legislating to minimize it. Then, when a new generation without this memory rises to power, income inequality grows again, culminating in years of unrest like 2020. Following this, policy changes again. I expect to see reduced income inequality in the coming years, in the form of 'techlash'. Read more about this in a very perceptive article that predicted 2020's social unrest here:
https://aeon.co/essays/history-tells-us-where-the-wealth-gap...