The US really can't win. If we didn't support Ukraine we would be blasted. If we do it's because we are just trying to enrich ourselves.
Quite a lot of those are older weapons that need to be either spent or securely disposed of within a decade or so.
Don't take me wrong, I am happy that the US helped Ukraine and I certainly wish that the next package passes the House, but the economic cost of your help isn't easily calculated in dollars. (Or, for that matter, our in Czech crowns.)
Stockpiles need to be either spent or renewed/replaced. Perhaps you could have used some of that older stuff in training, but not all of it. Military equipment has an expiration date, you would need to refresh your stockpiles anyway.
Today the US has two strategic enemies - Russia and China - and two strategic partners, Nato in Europe and everyone in pacific except China.
The US can spend peanuts - it really isn't a lot of money in US defence terms - backing Ukraine and using Ukrainian casualties to defeat it's strategic enemy, Russia, whilst making it's other strategic enemy, China, fear it.
Or it can waver and show it's no longer the leader of the democratic world and make all it's allies in Europe and Asia not believe in it.
My big fear is that it is empowering China to dare to have it's go at Taiwan in a couple of years.