Gini coefficients are somewhat critiqued in Graeber / Wengrow's Dawn of EverythingThe Dawn of Everything (they are somewhat dismissive of the whole question of "inequality" in the first place, which they argue, somewhat convincingly, is the wrong question)
nevertheless:
"The Gini coefficient, devised by the Italian sociologist Corrado Gini in 1912, is a measure of income or wealth disparity in a population. It is usually expressed as a fraction between 0 and 1, and it seems easy to understand, because 0 is the coefficient if everyone owned an equal amount, while 1 would obtain if one person owned everything and everyone else nothing."
social democracies "are generally a bit below 0.3, while highly unequal countries are a bit above 0.6. The US, China, and many other countries have seen their Gini coefficients shoot up in the neoliberal era, from 0.3 or 0.4 up to 0.5 or 0.6, this with barely a squeak from the people losing the most in this increase in inequality, and indeed many of those harmed often vote for politicians who will increase their relative impoverishment. Thus the power of hegemony: we may be poor but at least we're patriots!"
note that "[t]he spread between the richest and the poorest is an important consideration, but when everyone in that spread is pretty well off, this is a different situation than when everyone across the spread is por"
note that both Holland and Bangladesh each have Gini figures of around 0.31