The European Court of Human Rights is hugely important. From the right to an education to the right to vote, it covers and protects all aspects of our lives. The idea of losing it cause of some lies about “boat people” is terrifying and the effect on our lives untold.
Incorporatoon in the ECHR is an explicit tenet of the good Friday agreement. They cant pull us out without undermining that agreement, which would result in eye-watering sanctions from America and Europe.
(And also in any normal timeline - political ostracation. Although burning everything to the ground seems to be quite a popular policy these days.)