The US will take a 3 year project, bid it out as a 10 year project to "save money", and cancel it at year 20 for cost overruns and because it's not projected to be operational until year 30.

Stretching a 3 year project to a 10 year project costs way more money. Labor costs go up every year. My state DOT manages to complete their road projects on schedule, even the large ones.

I can think of a handful of projects that turned out like your example, California HSR and some nuclear plants. The vast majority of projects are completed on time.