The US can't ramp up their production overnight, because nowadays they are industrially weak, service and consumption based country and economy. The 80% of their GDP is consumption. Their industry is 20% of their GDP, but for example, China's is 40%. They are not manufacturing and export oriented nation. They don't have nearly enough millitary capacity as in the Cold War.
That is showing their whole economic model, of recent decades, for "growth", which is printing money out of thin air, debt creation, importing, and then reselling mostly Chinese goods to their citizens im Walmarts, Home Depots, etc. That's what "services" are to them.
Other than that, they have the most bullshit positions on the planet, the most lawyers per capita, bankers per capita, hedge fund managers, instagram influencers, youtubers, etc... Nothing of real value that can actually produce you something once a war-time economy starts. Even those 20% that is counted as industry is mostly general assembly relying on mostly Chinese imported parts. Meaning, they are industrial weakling.
It is nothing strange that the Russia, which has the nominal GDP size of Italy, 30 times smaller GDP than NATO, is out producing and embarrassing them so easily. Russia already entered full wartime production mode, now producing 7 times more millitary equipment, than before, where is the West?
They already did practically empty all of their and their vassals' millitary stockpiles of some specific types of weapons to give to Ukraine. First they stole Soviet origin millitary equipment from their Eastern European vassals to give to Ukraine, then they emptied Western European vassal stockpiles, but nothing seems to work. Because Russia is simply producing more.
They basically DO already keep Ukrainians afloat. The original Ukrainian millitary was already destroyed by Russia in those first few months of war. They are now fighitng against Western equipment's, instructors, ISR capabilities, and in many cases directly Western soldiers, especially the Poles.
Ukrainian economy is already destroyed, the US is giving billions of dollars each week if we divided the total amount given recently and the number of weeks. Ukraine would have folded 10 times until now if not the West. Ukrainian original economy and millitary are already destroyed, this is now Western stuff.
So, what I'm trying to say, it's not like the US did pull any punches against Russia, not even close. For example stealing Russian foreign reserves was such a crazy and self-destructive move that didn't even happen during Cold War.
It is just that you think that the US could provide them more weapons, when I say that they can't. The only thing the US could do is to provide more dangerous types of weapon systems, like fighter jets and longer range precise missiles, but guess what, they are already doing it!
As to why the US doesn't send it's own forces directly against Russian forces in Ukraine, like they prepare to send against Chinese for Taiwan, it's because Ukraine is objectively strategically irrelevant shithole which was the poorest country in Europe per capita even before the war, while Taiwan is global overlord of high end chips, the most advanced and precious technology that currently exists.
Why should they send their forces for Ukraine then? Also, even if Russia gets Ukraine, they are still stuck encompassed by NATO everywhere they turn, meanwhile if China gets Taiwan, it is free to roam Pacific. Not to mention China is a real superpower peer rival, meanwhile Russia is nowhere near that status as a peer existential threat like that. That's why they will go directly after China and not directly after Russia. Because Ukrainians are irrelevant fascist pawns while Taiwan is the real deal and the most significant territory in the world for this century.
