People quickly get used to other accents and dialects. Before RnaG existed, maybe it was more difficult to Munster people to understand Donegal people and vice-versa, but now people have got used to the other dialects. I spoke with people from Kerry, Cork, Connemara, Mayo and Donegal and none of them ever had difficulty to understand me (although you may have understood I speak Donegal Irish

with no standardisation at all). So I mean, you don't need to a standard dialect or of a Galltacht accent, people understand each other without difficulty, if they know enough Irish. I think it's even more difficult to a Gaeltacht speaker to understand badly pronounced standard Irish, than to understand another Gaeltacht dialect.
"The "Galltacht" way of speaking" is simply the way learners speak before they manage to speak properly. Most of the learners try to speak a dialect once they're getting fluent, because in all languages, the model to follow is the speech of native speakers, and in Ireland, native speakers don't speak Galltacht Irish or standard Irish, but Gaeltacht Irish.
