Ayn Rand explains how leaders with a collectivist mindset can justify such lusty sums for pet projects and public largess even though we are experiencing record inflation partly due to previous enormous spending. It comes from altruism, paired with a neurotic lack of self-esteem in a leader or among lawmakers that fuels the need for ever more spending on “the public good”. It is based upon the need to feel good, rather than actually doing good.
The public who support these policies get to feel good about themselves too, but only for a little while, until the bill comes due. By the time they're paying $5 for a loaf of bread, and $6 for a gallon of gas, it's too late.