Is decent infrastructure an impossibility?
In a technical sense, no? There's plenty of places where it's mostly fine, there's just... also a lot of places where it isn't. And the US is effing huge, so keeping it all in good shape is somewhat expensive.
... also a lot of the industries supporting it are corrupt as
fuck (road construction is just holy shit what the hell in a lot of places in the US, ferex), which doesn't help with the expense aspect.
Also doesn't help that spending has been fairly steady (relative to GDP, anyway), but we've been expanding our road system at the same time, which... should be an obvious problem. Can't really do sufficient maintenance when huge chunks of the budget are going into expansion (which further increases the maintenance costs and, well. Tantrum spiral.).
And other issues. It's a friggin' gigantic and hella' complex issue.
And yeah, multi-billion is almost understating it. 2014 spending was ~416 billion just for
public spending on water and transportation. To frame it to better contextualize things for you, OW, the US infrastructure costs in 2014 was around 2-3x New Zealand's total GDP. And it's still kinda' shitty in a lot of places. Basically it's not impossible, but it takes the concentrated effort of what's equivalent to multiples of entire countries, just to fail
slower.