>enjoying significant subsidies from the UK governmentThose subsidies don't seem to be enough to save it when the infrastructure is crumbling and everyone is moving abroad for jobs. Also, many countries don't need subsidies, they need opportunities. Subsidies are like paying a crackehead to buy more drugs instead of getting him a home, warm meal, a shower and schooling for job applications.
>money they likely wouldn't get from Dublin
They would get it from the EU then, and probably a lot more, as the UK gov is now struggling financially to stay solvent. The EU can very generous if you can play the game right. Just look at Poland 20 years ago and Poland today, the difference EU funds and the EU open market made, is night and day. It has also benefiter the Republic of Ireland. I doubt they would have been in the same state today without EU membership. For all its faults, the EU has been a force for good many times. Another English speaking region joining the EU could be a mutual benefit.