That's a great point.

This thought was sparked by reading a book where the author talked about modern slavery and sweat shops making products for the US consumer. They suggested if we consumed less this would somehow help these people.

I fail to see how it would. I don't have sources handy but I believe it has been well documented that globally massive numbers of humans have been lifted out of poverty. There is still inequality of course. Always will be. But the reduction in global poverty seems like a great thing to me.

It could be so much better if people could save their earnings in bitcoin though.

The US does clearly manipulate and use poor countries for the profit of corporations but this isn't a flaw in free markets but rather the result of centralized power. And even though this is global prosperity increases with access to free markets.

More central planning will result in poverty and starvation.

I think the consumerist lifestyle is just largely fueled by cheap credit and the discouragement of saving caused by fiat money printing.