If one were to say the industrial capability of US is a dwarf compared China, it would also not be wrong to say that Russia's industrial capability is a dwarf compared to US.
So vis a vis Russia, I'm sure that if US prioritizes arms, they will easily be able to supply Ukraine and their volunteer forces with adequate equipment.
But in practice it is not that easy. America's real target is China, if the world's largest economy with a huge bloc of the world's population under them can't be defeated or at least contained, then any US ambitions of imposing their "order" on the world is gone.
Each equipment, each value of currency, each industrial sacrifice sent to Ukraine, is a distraction of much needed resources. The Ukraine front will never hurt China no matter what the result becomes, but it can hurt NATO if they fumble it.
If NATO overcommits their industry and manpower, they will have weakened themselves at 0 cost to China while the latter is just continously growing stronger. So if US mobilize their economy, they need to defeat Russia in the shortest amount of time, but the chances of that are low, and there is no telling how a defeated Russia would even react. Plus there is always a (large) risk that China will put its own industry behind Russia if Russians are being defeated due to NATO openly marching in with state of the art equipped "volunteers".
Then, the situation will turn around. Instead of US fighting Russia to the last Ukrainian, it will be China fighting NATO to the last Russian. This is not favorable for NATO.
The ideal situation for NATO is probably that Russia can be battlefield defeated by light volunteers and donated equipment only, driving Russia deep into the Donbass and away from the South(Kherson, Mariupol area). Then, Ukraine can sign peace with only minimal territorial losses around donetsk and luhansk, while keeping complete access to the black sea. Pushing any further than that, risks involving the whole Eastern bloc.