"In case you hadn't noticed, Irish music is played here too, and my comparison was with the Irish music scene in the UK."
You don't know anything about the Irish music scene in the UK, and certainly not currently in Ireland, so how can you make a comparison ?
"My only experience of the music scene in Ireland was 30 years ago,"
Exactly. See above.
"Ireland doesn't have "music buffs", they have musicians who play traditional music.
You were the one who introduced the label.

"There have been books of Irish polkas in the past"
Please list them [ plural ].
" but who would use them now? Would anybody in an Irish session these days point a newcomer to one as a standard reference?"
No. They don't need to.
The discussion is about "folk music in the UK". Now certainly, politically, a geographic part of Ireland is in the UK, so if you know about the current situation of "the folk scene" there, please feel free to enlighten us. Nobody so far has done in about 1600 posts.