Once the US pulled of the completely absurd task of putting a man on the moon and then returning him safely to earth, in less than a decade. All the incentives were aligned, it had public support, and a huge amount of resources were mobilized and ready to deploy.
We're not deploying huge resources on our infrastructure projects, we're piecemealing them. I've got a branch rail line going in at the end of my street. [1] The public input/planning process went on for years, and only now are they starting to relocate utilities, put up fences, etc. There's no one entity in charge of all the layers of the project, it's all hired contractors and inter-agency cooperation. It will be done, likely in 3 years or so. This line is a total of about 9 miles long for about $945 Million.
The worst part about it for me is the insidious nature of the funding they're using. They're doing "Tax Increment Financing" which means that any increase in property tax revenues theoretically caused by the "improvement" of my house go to pay off the construction bonds.
Let's say there is NO improvement, but inflation doubles taxes in the next decade. The town now gets the same dollar amount, but half of the funding it used to get, and the rest goes to the bond holders. This will strangle our schools which depend on local real estate taxes.
[1] - https://en.wikipedia.org/wiki/West_Lake_Corridor
PS: Just across the state line is a defunct Country Club, which is in close enough to the station to qualify for "TIF" improvements, and the husband of the local State Representative pushing for the project, just happens to be the a real estate developer interested in said property.