Very true, regarding Zionism's poor timing in that regard. However it couldn't be helped. I argue that even more than early-20th century pogroms in the east & the Holocaust, it was the Allied Powers' lack of action, post-war, that demonstrated the need for & validity of Zionism.

The ME is chock-full of should-haves & would-haves. E.g. Palestinian Arabs were offered an opportunity to form a government under the Mandate that would have left majority-control with them, but refused to have any part of any government that involved Jewish participation, despite an ongoing presence in the region that predated their own.

Another commonality Israel has with the US is that extirpating Jews entirely from the region (or are we to leave 3 - 4% to mirror pre-20th century levels?) & returning it all to Palestinian control is no more realistic than plans to return the North America to the Indians. As Walter Laqueur wrote in his history of Zionism, the Jews in Israel believe there, in their own country, they would go down fighting rather than allow themselves to be carted off like so many sheep as minorities in someone else's country. As Israel is a nuclear power I don't see how your proposal is anything more than a proposal for widespread destruction.