While Israel was created “out or air” so too were the states of Lebanon, Jordan, Syria, and Iraq. Israel appeared, and a state of Palestinian would have a appeared if the Palestinians accepted it. They were given their own state at the exact same time. But they refused it because they wanted to kill all the Jews.
That land was sparsely populated, and very underdeveloped. Jewish immigration prior to WWII began to develop the area. This attracted more Arab immigration as well. This region, prior to those migrations, was barely populated, certainly not enough to constitute a state.
Palestinian statehood didn’t become a slogan or idea for the Palestinians until the 50’s or 60’s. Well after they were offered a state and rejected it.
The goal since the beginning as been the extermination of the Jews, this continues today, veiled under slogans of “from the river to the sea” and the slippery “two-state solution”. Every two-state solution offered to Palestinians is rejected by Palestinians. Because they ultimately want a one-state solution with no Jews in it.