Broadly speaking we tax wealth creation but not wealth retention. That's hardly a model to either ecourage hard work and creativity or build an egalitarian society.
I do agree that many of regions are a lot less wealthy than Dublin, and that a stroll around most regional towns and places like Limerick and Waterford City present a very different picture than the narrative we are fed.
Dublin's north inner city is a drugged out wasteland, buildings sprouting buddelia on every side, crime statistics way beyond anything else in the country.
Limerick and Cork are a paradise by comparison, plenty of employment and much cheaper housing, less drugs and far less crime.
While this is not directly connected to the poverty in Dublin, it certainly makes for a far better standard of living.