I have a personal belief that this is a result of the "can-do" attitude that pervades not only American society currently; but virtually all of American history.
A small group of colonies managed to win a war against what was considered at one point the globe's strongest empire. Throughout the history-narrative of America there is a prevailing sense that the underdog can always overcome their circumstances and win the day. That most Americans (myself included) have a semi-deluded sense they "can achieve anything they put their minds to" is a direct manifestation of that narrative-history. It's also why there is so much rampant anti-intellectualism here; think about it, if you can do and are capable of anything - why would you *ever* listen to an expert's opinion? It's also why libertarian-ism is so popular; why would you want the rest of society dragging you down when you yourself are capable of so much more?
I want to be clear as well, there *are* benefits to the can-do attitude, but at this point the cons outweigh the pros, and we are seeing that play out in American society. I'd also like to acknowledge that the current situation is the result of many different factors; but that this one is largely overlooked due to the assumption that it's positives outweigh it's negatives.
Political elites in a vast colony far from the empire’s center gambled that the empire did not have the will to grind out an expensive victory against fellow elites. This proved to be correct.
I think there's something to this. And while America has always had this can-do attitude (just look at the number of self help books), it does seem to be in another gear recently. I don't know what caused it, but I think there have been a number of indicators: Trump ignoring Congress and introducing wild tariffs, Musk firing half of Twitter's staff and then later repeating this with DOGE, the quick roll-out of LLMs. There seems to be this prevailing attitude of "we can just do stuff, damn the consequences".
It appears to come with a lot of corruption and anti-intellectualism. Like you say there are also benefits to this. I think the break through of mRNA vaccines was an early indicator. I just hope we can steer this attitude back to a more optimistic world-view instead of the blatant self serving one that is currently prevailing.
Well, yes and no. A can do attitude is needed to imagine taking over fighting a global British empire. All around the world people needed to muster up that courage. That said, equating the outcome of that with smartness was bound to happen. That said, they leadership got co-opted by money outcomes is where the downfall happened, IMO