Those cultural ties will take tens, perhaps over 100 years, to weaken enough to cause a civil war.
Unless it decides to go down fighting and gets something important blown up it could easily remain a nice place to live for centuries. Nobody threatens the US, it is hard to see how it'll ever be in anyone's interest to threaten them, they can re-learn how to be an industrial powerhouse if they have to. Almost all its real problems are ill-advised domestic policies that can be changed pretty quickly if people decide the situation is hairy enough to be honest in politics.
It might be in everyone's interests for the US to dissolve but it won't be as bad as the USSR dissolution was. It'd probably be a good outcome if they went back to the constitution as intended, depowered the federal government and became a collection of powerful states. A lot of the political tension is because whoever wins the fight over controlling the central government ends up with far too much power.
We’ve offshored manufacturing, cut funding for education, have failed to invest in infrastructure.
https://www.macrotrends.net/global-metrics/countries/USA/uni...
Education funding per pupil has steadily increased year after year. Maybe we should spend even more, but our problems with bad educational outcomes are mostly due to other factors rather than a lack of money.
https://educationdata.org/public-education-spending-statisti...
https://www.axios.com/2021/06/17/automation-ai-income-inequa...
Even if we bring back all the manufacturing jobs we've lost, they represent fewer positions and automation will continue to be a downward force on wages.
[0] https://ifr.org/ifr-press-releases/news/global-robot-density...