The delusion is to imagine that the Arabs of the Levant came from the Levant. They came from Arabia. It’s not their land. All Arabs everywhere in Northern Africa and the Middle East came from Arabia. For example, the Arabs in Tunisia came from Arabia. The indigenous people of Tunisia are the Berbers.
On the other hand, many of the European Jews can trace their pre-Diaspora ancestry to Judah and Israel.
And no, the Irish are not from Ireland if you go by their mitochondrial DNA. All Europeans, bar very few exceptions, are descended from 7 mitochondrial haplogroups which are spread across Europe (and beyond) and overlap each other.
Indeed, the delusion here is to believe that the Irish came from Ireland.