It is, because it's used to drive agendas.
It's not a direct measure of poverty and in fact some of the main ones used , based on relative incomes are misleading too, as they are treated as difinitive measures and are actually just relative to what you also point out is a generally well off society.
By using these bollox measures attention is taken away from the true drivers of poverty.
Lack of ambition, mental illness, alcohol, drugs, crime, poor education standards , ridiculous house prices in some areas due to investment all being channeled into certain areas, etc...