It's not only about GDPR. It's even more about profit shifting and low taxation of big tech. Ireland has been selling out EU on digital front for over a decade.
In the EU, they've had the GDPR – a big, muscular privacy law – for nine years, and all it's really done is drown the continent in cookie-consent pop-ups. But that's not because the GDPR is flawed, it's because Ireland is a tax-haven that has lured in the world's worst corporate privacy-violators, and to keep them from moving to another tax haven (like Malta or Cyprus or Luxembourg), it has to turn itself into a crime-haven. So for the entire life of the GDPR, all the important privacy cases in Europe have gone to Ireland, and died there:
Now, again, this isn't a complicated technical question that is hard to resolve through regulation. It's just boring old corruption. I'm not saying that corruption is easy to solve, but I am saying that it's not complicated. Irish politicians made the country's economy dependent on the Irish state facilitating criminal activity by American firms. The EU doesn't want to provoke a constitutional crisis by forcing Ireland (and the EU's other crime-havens) to halt this behavior.
Oh, aren't many of big tech's EU HQs in Ireland?