"Helicopter money, for example, does not intrinsically add, it carves out a liability somewhere."

On the contrary, helicopter money ADDS purchasing power, which then TESTS productive power. IF the productive power is there, the helicopter money elicits it and CAUSES growth and wider prosperity. If the productive power is there, the helicopter money causes inflation, which restores the balance between purchasing power and productive capacity. Money is never "just lying there," but productive power may be, and printing money is how we put that power to work.

There is no absolute answer to "can we afford it?" The answer depends on whether we have the NON-FINANCIAL resources available to do it. In times of technological advance, we tend to underestimate our productive capacity. It happened in the 1896 and in 1937, and it is happening now. The internet indeed changes everything.

Whether all of Biden's ideas are good is subject to debate. I assume some of them are foolish. But for the most part, infrastructure upgrades pay for themselves in the way that all maintenance pays for itself, by avoiding losses from system failures. Future generations are going to USE the enhanced infrastructure, so they should "pay for it" out of the money it saves them.