I’ve read studies that say at least genetically, both Israelis and Palestinians share roughly the same amount ancestry from bronze age levantine populations. That being said, the Palestinians did not expell the ancestors of the Israelis from the region, they seem to be descended from the people who stayed who then assimilated into arab culture/intermarried with other Arab populations. If the Israelis really wanted their homeland back they would’ve allied with their Palestinian brethren and nuked Rome or something.