> The NI/RoI divide is no longer seen as purely sectarian, due to the increasing secularisation of both states and also because the RoI has quite a few Protestants doing quite well.
I went to County Cork about 3 years ago and the Church of Ireland churches seemed at least to me nearly empty of congregation members, even during services. Inside were mostly staff and tourists. The Catholic attendance also seemed lower than I expected, but the Catholic church congregations there still seemed to be substantial. Maybe County Cork is an outlier?
The republic a few years ago was so religious it was a defacto catholic theocracy. That the fact that Church congregations are still substantial is relative when you consider how much power they used to have but no longer have.