I dont buy this we were first to do it. Plenty of other countries do continual upgrades to subways, banking, bridges, financial systems etc. My reasons are partly these;
1) I think US tend to think of itself as No.1 nation and makes it less likely to look at other countries doing things better and looking to follow. I think this becomes a mental limitation for many US citizens and policy makers.
2) There is too much corporate capitalism. Money in politics etc. Look at the internet system where Google tried to roll out fibre and there were regions passing laws stop competitors even going into the market. Look at the prices you pay for mobile services. For the world leading free market, there is way to much corruption where markets are restricted rather than government pushing to open established markets to new business when they become entrenched.
3) Over investment in military. US could have that budget, still be the largest military by a mile and be dropping hundreds of billions in building and repairing infrastructure.
4) Too much focus on making money vs doing things well. The desire to keep building a nation seems to be gone. same in my country of Australia. You read history from earlier in the 20th century and they had a view to get things done that would benefit a nation overall. Now its 'would a rail line really pay for itself and be cost effective' type mentality that limits visionary projects.
5) Career politicians. Like other nations I think many career politicians want to take the safe route for reelections. There is endless media criticism of these guys if something goes wrong, and big projects, things do wrong and no-one wants to hear were putting up taxes this year to pay for stuff. No idea how, but we need to filter better for people that believe in what they are doing and have a vision vs popularity based vote for me campaigning. And generally vet them for brains and ability vs I always vote for this party.