The concern that Ireland relies on a small number of taxpayers for a significant part of its tax receipts is reasonable. Who are these large taxpayers. Among the largest tax payers in Ireland (2021) are 1 Apple 2 Microsoft 3 Google 4 Pfizer 5 Merck Sharpe and Dohme.
These are among the largest companies in the world, with a good spread between Tech, Pharma, Med Devices and Head Office Services. Much better to be taxing the world's largest companies than, well than anything else.
Of course in time some of these companies will fall away, but Ireland's success in attracting them in the first place suggests that we are well positioned to continue to attract their successors.
The one thing that might stop us is our failing infrastructure. With a successful economy building infrastructure is difficult and expensive. Waiting until our economy decays due to the bottle necks and then building when there are lots of unemployed labourers hanging about is well, nonsense.