Yes, GDP figures for Ireland and other small open economies (and, for that matter, _London_, which has the same sort of dynamic) are pretty useless; this is fairly well-known. However, Irish average wages overtook UK ones after the financial crisis, concrete economic activity is generally higher (for instance, Ireland builds about 2.5x the number of housing units per capita per year), the Irish state pension is higher, Irish unemployment is lower, Irish inflation is much lower, and so on.

And it’s much starker when you compare Ireland to Northern Ireland (the bit of Ireland that the UK still runs), or, really, to the North of England or most other UK regions (again, really, the whole UK economy hangs off the south-east). The idea that Ireland would be _better off in 2025_ if it had stayed part of the UK is… pretty out-there, to be honest. The UK is simply very bad at regional development.

Ireland _was_ an economic basketcase for a very long time, but then, realistically, so was most of the UK; more or less since WW2 the UK outside of London and the south-east has been looking pretty unhealthy.