The reason WRC is important is that this is not about today and the six trains you mention, this is about the future.
Going on that logic the Harcourt line in Dublin should have been built on and there would never have been a Luas because putting that type of infrastructure in place today would be impossible.
Brexit means Rosslare is more important and links to it by rail are a solution for the future. Ireland is obliged under UN sustainable goals 2030 to move away from car/truck petrol-diesel as all our fuel is imported. Electric trains will be the way to go. Dublin Cork line is too busy.