I don't care, what the world bank says. It is statistics. For example: How do they define "poverty"? By manipulating the definitions, I can prove anything to you.
It is a fact (and in my country, you can see it in the media), that in the developed countries, the rich got far much richer than the other people got.
That maybe some people in lower developed countries are better of now (by the statistics), might be, but their income is so low, that they do not really count against the growth in income in the other countries.
Please, don't tell me about the world bank. I don't trust organisations, that are installed for one main reason: To sell capitalism to the world.
The numbers from independent researchers are different. Read the book from Piketty:
Of course, if you read the right (right-wing) media, they will try to discredit it, but I did not yet read any plausible critic -- only wild tries to protect capitalism from any thinking.