Dictatorships enjoy vanity projects such as underground railways, giant stadiums and colossal government buildings.Algiers
Baku (thats in Azerbajain btw)
Minsk in Belarus
have all opened undergrounds in the last 5 years
You saying we're poorer or less capable of building infrastructure than them ?
Its fairly simple ....
1. especially in a city with narrow roadways like Dublin ...if you have no extra capacity on ground level (none zero zilch) , no space above ground level ...then the ONLY solution is underground
2. It never gets any cheaper than Today!!