A lot of focus has been on how much is owned by the top tier. (40% by the top 1% and 50% by the top 2%, 85% from the top 10%)
I think it is more important to note how India and China are developing and helping many of their people move up. Poorer nations face many obstacles to amassing wealth, including sketchy property rights and land tenure systems, and underdeveloped financial markets. So it is possible for countries to fix their systems and get onto the development track.
People can also study and see how individuals become more successful within countries. Such as the millionaires and billionaires in the United States. If someone is in a developed country they can change what they are doing to improve their situation.
Someone in Africa either has to become a successful warlord or has to leave and escape the area and get to someplace where they can do better. Note: even within developed nations and regions, some places might be a better match to ease your own path to wealth. Location, location, location is not just advice for real estate but for ideally locating yourself to optimize your chances and situation. The report is telling you that some countries are loser countries. Some regions are loser regions. In a lot of places that will not change. Winners will keep on winning. A few places can change, but it will be apparent years in advance who is turning it around.
Someone who is in the United States (or anywhere else) has to look at moving beyond low skill salary work and master advantages for a successful business or some form of investment. This advice is advantages, advantages, advantages. If you really want to do well then you must figure out ways to do what you do better than your competitors. Better means having lower costs, being able to sell at higher prices, being able to add value, being able to complete transactions faster etc... The report is also saying that some people and personal strategies are winners. If you are not winning then you are and will stay a loser if you do not change.