There are 2 debates, the first is about if the island is the primary topic or not or if the country is the primary topic or if there is no primary topic and the disambiguation page should be at "Ireland". It is argued that the island serves as a broad-concept article but also that the country would be a better topic even if narrower.
The other debate is what the title of the country should be if it isn't the primary topic.
Proponents of using the title "Republic of Ireland" argue that its common usage and is the country's official description, see Names of the Irish state.
Opponents argue that the name "Republic of Ireland" is unofficial and incorrectly convoys the name of the country and that it would be better moved to something like Ireland (country).