Pretty much every country on this planet is not populated by people "native" to that country. So saying Israel has no right to exist based on this argument while applying that argument only to Israel is discriminatory. This is before we even address the question of whether this claim is even true or how it is to be judged. If someone's political opinion is that everyone should move back to where their ancestors lived at some specific time in history and they apply it to everyone equally then I would think that's weird and not going to happen but I'd be fine with that.

Typically I don't like to engage in political discussion about the middle east because most people have no clue about the history of the region and interpret what's going on over there through some lens with a very shallow depth of field. That tends to apply to Israelis as well. That said I think antisemitism is still a concern that we have to speak out about and definitely some modern incarnations of antisemitism are directed towards Israel. That doesn't mean that any criticism of Israel is antisemitic but it's just something that makes things more complicated.