If we were numerous like that, and not such a tiny minority of the world’s population, the experience of being Jewish would be totally different. The Egyptians feared that that would be the case (Ex.1). But the fact is that we never covered the face of the earth, and large numbers were never the criteria for Jewishness.
Without the many centuries of antisemitism more Jews would have survived; without the drift away from Jewish identity and commitment our numbers would be greater; with more converts entering Judaism our ranks would increase; but we would probably always have been a minority.
The great legal luminary AL Goodhart argued that there was even an advantage in minority status. A minority has courage to be different. It does not accept the status quo as the only option. It thirsts to make the world a better place. It never has the luxury of sitting back and relying on other people to do whatever needs to be done.
When space travel developed, some religious leaders argued that the skies belonged to God and we should not attempt to challenge His rule; at that point Gorbachev is said to have snapped, “And how many legions does God have?”
Good rhetoric, but it is not necessarily important to have billions of legions. A people can live without vast numbers provided it has a fierce commitment to its ideals and its destiny.