Broadly False.
Look at the GDP per capita growth of Ireland and match it against a graph on corporation tax in Ireland. They implemented a 12.5% corporation tax rate in 2001 and well look at the acceleration despite a dip for 2008. This is primarily responsible because otherwise why is the rest of Europe doing crapper than we are?
Brexit isn't really featured but of course Ireland may become attractive but that's primarily because taxation is low and companies think hey let's move to Ireland to position our company in a favourable tax system for Europe. The UK was never a low tax haven country prior to Brexit so not much has been lost.
Brexit isn't the prime problem but what is certainly featured within the degradation here are the actions of successive Conservative governments.
