It is a noble lie, told repeatedly until it is believed by all. There for the sole purpose of limiting government power over the resources of the nation.
You’ll note that in times of war, there is never an issue of money. Nobody ever stops to check the budget before they launch a bombing mission.
So no, we don’t need the savings of the rich to reach utopia. If there are people available willing to build the new future, then the government can finance its construction.
Which means that we can end poverty and appalling work conditions at a stroke with a Job Guarantee — an alternative job offer at the living wage, and with acceptable working conditions, working for the public good.