This question shows a fundamental misunderstanding. Before the establishment of the modern Israeli state, most of the Arabs living in the region were actually of Egyptian or Jordanian descent. There was no Palestinian people group until after that so as to identify the displaced Arabs as one group.
Jewish people, however, have lived in and been associated with the land for thousands of years. Palestinians are categorically not the same as native Americans.
There must be a separate, sovereign Palestinian state - because that would be most just and fair. There must also, however, be a sovereign Israeli state because of the historical ties to the land and the fact that for millennia the Jewish people have been persecuted wherever they go. I honestly don’t know why, but they have.