Why is it that American government ends up being massively inefficient?
Part of it is that a huge number of people are tasked with enforcing a truly mind-boggling number of laws – I've discussed here that minimizing the size and scope of government should help.
But another part is that our governmental organizations are not set up to strive towards achieving their goals effectively. Are subways getting built quickly, cheaply, and being made to a reasonable quality? If not (and they definitely aren't), why not? Answer the question carefully and extremely specifically, and implement systemic changes to achieve a better outcome.
That feedback system is the mark of a high quality bureaucrat, and is exceptionally rare. I guessed, when discussing this in person, that there are perhaps 100 effective bureaucrats in America total, and most of those are working in non-profits. There simply aren't schools that teach a high enough level of systems thinking, management, and active engagement and curiosity with details of a complex problem. Those could exist, but they do not – Harvard MBAs might be impressive, and useful to McKinsey to hire them out to explain the basics, but actually trying to understand a novel part of the world in enough detail to remake it better, that's simply not in the coursework.
Needless to say, the internal incentives for a system (keeping unions happy, making your boss look good, avoiding high profile mistakes at the expense of lower profile successes) prevent a lot of these changes. But many places resolve them.
For instance, I remember hearing about the UK setting metrics for how quickly their public hospitals handle patients. They ended up accidentally incentivizing "hello nurses", who merely greet a patient to lower their time-to-first-interaction. At this point, you can try to avoid the problem more, and engage in more detailed management, or you can notice you made a mistake in your metric-setting (notably, trying to proxy consumer preferences), and went to a public insurance option that lets people choose any hospital they want knowing the system would have fixed reimbursements per medical result. That way, people that want to pay more can get a fancier version, but it comes out of their pocket.
Instead, in America, you can have decades of general knowledge that VA hospitals are terrible, tons of support for change in Congress, and the problems never get addressed meaningfully. Reasonable bureaucrats can make some progress, but never truly fix major problems. The institutions are not built to support increases in efficiency, so no one ever learns how to do anything better. Almost every functional institution has a schedule, telling you when important information about how their job is done comes in and changes what happens. There's indirection, agility, and change built into their DNA.