Putting aside the big issues with using the Gini coefficient as a measure of income inequality (very different distributions can have similar Gini coefficients)

Putting aside the big issues with using the Gini coefficient as a measure of income inequality (very different distributions can have similar Gini coefficients) - and the even bigger issue of ignoring wealth altogether - the World Bank data relies on household surveys which are notoriously unreliable even in Western countries. Those numbers ought to be taken with a big heaping of salt.