Indeed, it is Palestinian territory. That is what the UN said in 1949. I have seen nothing since then that changes that.
Neither have I. It IS "Palestinian territory". All of it. That "Palestinian territory" is now the State of Israel.
You are trying to argue that the State of Israel does not exist. But it does. According to the criteria that you supplied, and according to all known understanding of international law. According to the parallel examples of Jordan, Syria, Lebanon and Iraq.
There is no logical, legal reason WHY the "Palestinian territory" you speak of can not be = State of Israel.