> A dollar is an entirely fictional unit and trillions of it can be manufactured at no cost

It’s still a useful proxy for resources allocation and viability.

..unless you're actually reasoning at nation-scale where OP's points apply

	▲	ElFitz 4 days ago \| parent [-]
		I wouldn’t agree. Even at national scale, these projects cost resources. And the resources of all agents (org, countries) are constrained. While we could reason in "performance / watt" and "performance / people", "performance / whatever other resource involved", and "performance / opportunity cost of allocating these resources to this use case and not another", "performance / whatever unit of stable-ish currency" is a convenient and often "good enough" approximation that somewhat encapsulates them all. A simplification, like any model, but still useful.