Not quite, we changed our priorities considerably. The US shifted its government expenditures to welfare, entitlements and standing-military spending. The US has dramatically expanded its social safety net over the last four or five decades. You can see that by checking the federal budget by decade and how its allocation has changed. Properly few voters want to go back to 1955, they'd rather we continue paying for free healthcare for the bottom 1/4, at a cost of ~$650 billion per year. If you give those people a choice between national high-speed rail and their health coverage, they'll choose health coverage every time. The mistake in the case of the US, is in not having built eg high-speed rail when it could have done it, before welfare and entitlement spending demands got so massive.
In short, the US system, the social contract, has fundamentally, permanently changed. There's no scenario where it will or ever can do infrastructure like it did 60 or 80 years ago, because the government allocations can never be like they were. It's comparing two entirely different systems of spending demand & allocation, along with entirely different social expectations.
China is currently undergoing exactly the same transformation as it seeks to build out a social safety net. As that proceeds, they'll no longer be fiscally capable of the infrastructure spending they've been undertaking the prior ~20 years. Social welfare spending demands will rise perpetually, particularly given the rate at which their society is aging. Right now the average pension in China is about $200 per year, and their pension system is already financially tipping over. That won't stand, China will be forced to allocate dramatically greater spending to social welfare over time. China is about to start running twin deficits, on their fiscal budget (already bad) and their trade. I don't see a scenario going forward where they can both meet the social demands of an aging population that wants a far greater social safety net and the free-wheeling infrastructure spending behavior of their past. They'll be forced to choose, as every other developed nation has.