The Jewish National Fund raised money to buy land. It expelled no one. The purchase of land for Jews to return to their historic homeland began back in the 1880s. These purchases involved no forcible expulsion. You’ve invented a myth the land then had a substantial population of Palestinians. It didn’t. Back then the people there were very few and they did not think of themselves as Palestinians. The land was largely unpopulated and undeveloped.
Mark Twain wrote
There is not a solitary village throughout its whole extent (valley of Jezreel, Galilea); not for thirty miles in either direction… One may ride ten miles hereabouts and not see ten human beings. For the sort of solitude to make one dreary, come to Galilee… Nazareth is forlorn… Jericho lies a mouldering ruin… Bethlehem and Bethany, in their poverty and humiliation… untenanted by any living creature. — Mark Twain, “The Innocents Abroad”, 1867
The Dome of the Rock in 1875 was in a state of abject disrepair.
The region was part of the Ottoman Empire. There were a small number of Arabs there. There were also Bedouins who seldom had formal ownership of fixed plots of land. There were very modest numbers of people in Jerusalem, but Jews were a majority.
Over the years, Jews developed the land and did make the deserts bloom. Barren land was purchased, incorporated into a Kibbutz, and developed until it became productive. Major advances were made in water conservation and irrigation.
Arabs immigrated in large numbers, coming from outside the region that would later become British Mandate Palestine after WWI. Most Palestinians in Gaza can trace their lineage to Egypt. Yasser Arafat, founding leader of the PLO, was born in Egypt. Other Palestinians have roots from areas that become Jordan, Lebanon, Syria, and Iraq.
No one lost their land before 1947, except for the Jews who were murdered and forcibly expelled from Hebron in 1929. Arabs rejected the UN partition plan in 1947 and Arab nations invaded the fledgling Jewish state of Israel. Some Arabs were coaxed to leave their homes by Arab leaders intending to give their armies free rein. Others left because they were near war zones and battles. Those who left ended up as refugees. Those who stayed became Arab citizens of Israel.
Jordan ruled Judea and Samaria from 1948-67 and Egypt ruled Gaza during the same period. No one thought those regions were Palestinian lands or should be part of a Palestinian state, least of all the people who would later be called Palestinians.
Take a trip to Israel. Enjoy the very fresh produce. Tour a farm or two. Examine the irrigation and water management. Buy some flowers. Then tell us it is a myth the Jews made the desert bloom.