China is installing something like 500 GW of wind and solar per year now. Even if they're only able to build and otherwise access chips that have half the SoTA performance per watt, they will win.
It’s still a useful proxy for resources allocation and viability.
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.
If the abstraction works better for you this way, call them interchangeable units of American and Chinese insolvency. Or incremental forfeiture of domestic ownership.