years ago the best ticket was an all-routes coach/bus/train one which gave you something like any five days out of seven.......
it was useful if you wanted to travel up/down the west coast and not just to/from Dublin
IF it still exists it may be the better option
There were a few different multi-modal tickets, the most complete was the Emerald Card which covered all Irish Rail, Bus Eireann, Dublin Bus, Northern Ireland Railways, Ulsterbus and Belfast Citybus. 20 years ago it cost around IR£100 for 8 out of 15 days.
Sadly these were discontinued at some point around 10 years ago.
As you say, even for someone who is only interested in Rail travel the mainly radial nature of the network means using some bus routes to avoid constantly doubling back to Dublin is useful.