And the ancient Israelites descended from people who came from outside of Israel. You cannot simply ethnically cleanse land of people whose families have lived there for many generations just because your ancestors also lived there long ago. I do not believe Jews should be excluded from Palestine either, just as Palestinians and other Arabs tend to believe. But the modern state of Israel is a settler colonial project that does indeed push out others with rightful claim to the land. The only reasonable solution, at least if we are accepting the framework of modern states, would be for Israel as it exists today to be dissolved, and the whole land formerly known ubiquitously as Palestine to become a secular democracy without prescription for religious and ethnic supremacy and exclusion, with the right to return for displaced Palestinians. This also respects the rights of many Israelis who, at this point, are multigenerational, and many of whom know no other home but Israel.
I should also point out that your portrayal of Arabs as a war-making monolith is extremely reductive and racist. Just as is your conflation of Jews and Israel.