Nobody hosts datacenters in Ireland because of capacity reasons. It's not a good location for power, people or connectivity. They host them there for tax reasons. You can bet your firstborn these datacenters are only the exact size that is the minimum allowed by tax law, not a square millimeter more.

Yes, datacenters are critical internet infrastructure. But in Ireland they're more like a sailing ship with the sails mounted underwater, because that's cheaper for tax reasons.