The investment is massive, but not bigger than other projects by an order of magnitude. Major wars were bigger than AI. The dot com bubble was 2-3T dollars.
Yes, the absolute numbers might now read TRILLION instead of BILLION or MILLION, but the concept of "Technology so impactful governments shift their economies" is in no way new, and has already happened a bunch of times before in humanity's timeline.
I guess that's why you're seeing some of us less stressed out about it, as again, scale is different, because scale today is different in everything, but relatively, we're just repeating another of those "Technology changes everything" milestones that we've done before.
When have we seen anything like this?
The US canal and railroad boom in the 1800s definitely had exactly the same thing happening, just compared to our scale today where everything is "more" and "bigger", it looks comparatively small. But in their world, back then, it was basically the same thing, just with canals and railroads. Indiana almost financially ruined itself because of their "infrastructure program". The government got involved heavily with the "1862 Pacific Railway Act" as well.
And yes, easy to say now that "Duh, that's essentially infrastructure" but at the time, that wasn't as obvious to everyone, as and railroad were newfangled technology, especially deployed like that, on a scale never seen before.
And faster. More, bigger, faster. Which substantively changes the situation the same way a musket stops venn diagraming as a “firearm” at some point when compared to a 50-round automatic rifle.