New approach to public transport
Of course, Ireland is less densely populated than Germany on average. However, there are well rural regions in Germany that are similarly populated as Ireland and have well working rail services. The usefulness of public transport in rural regions depens much on local politics. While there have been the strong political will to keep or restore passenger rail services in some regions and to deliver regular local links on demand, there has been nothing like that in other regions.
Nevertheless, integrated planning of Irish Rail and Bus Éireann services to end running busses and trains along the same route and timetables that meet the needs of people will surely work as well in Ireland as in other European coutries. We can all learn lessons from Switzerland which has an integrated network of public transport all over the country. In Germany, North Hessen is a good example for local links on demand every hour till just after midnight covering the whole countryside. Regular local links feeding into busses and trains furthermore bring additional passengers. The newly established local links in Ireland make sense, but need to run hourly and two-hourly in the catchment area of a train or Bus Éireann stop.
As Ireland is largely not densely populated, train stops on demand make much sense. At first, Craughwell and Ardrahan on the Galway - Limerickk route come to my mind. I know that the Rosslare - Waterford section is closed by now. But this line could be brought back quite easily into operation. To attract additional passengers, Rosslare - Waterford - Limerick trains have to suit with ferry timetables and offer links to other trains along the line, above all to Cork city. This line is as well a candidate for stops on demand. If Dublin - Limerick services are lead via Nenagh, Limerick Junction will be eased of these trains for the benefit of links between Rosslare - Waterford - Limerick and Dublin - Cork/Tralee trains.