I think some people don't yet understand why the tech giants have HQs in Ireland?
In order to trade FREELY within the EU (whether that's selling a product or a service), you need to have a company registered in an EU member state. You could put it in Spain, Portugal, Poland, Germany, Ireland etc. You could also have headquartered in the UK before they left the EU.
You can of course trade with the EU from outside the EU, but you'll pay tariffs, so it's cheaper to set up an arm of the company in an EU state.
Ireland was the location of choice for a lot of the US multinationals because they're English speaking, have a low corporate tax rate, are EU members and have the skilled workforce required. You also get to drink a pint of Guinness when you're visiting which is of course extremely important. You might even get a chance to look up your ancestors 😆