It's interesting that the more advanced an economy is (and thus presumably the more access it has to machines and technologies that should speed up construction

It's interesting that the more advanced an economy is (and thus presumably the more access it has to machines and technologies that should speed up construction) the slower it actually constructs buildings and infrastructure. There are a wide number of factors involved and their relative contribution is difficult to determine. Of course for starters people in advanced economies expect more of their buildings - they are built to higher standards and have more complex features which take more labor to produce. Verification that these higher standards are being met is likewise a more involved process. Advanced economies also have much less tolerance for risk - they sacrifice speed for safety both for the workers building the structures and for the end users. Additionally, workers in advanced economies tend to be less willing to go into manual labor fields and operating more advanced equipment requires more skill, requiring those who do go into the field to specialize, and thus while technology may make workers more productive this is offset by having fewer workers on any given project. Then, advanced economies tend to already be built up - you're either building in an already bustling area where extra measures must be taken to prevent disruption, or you're building in an area that was passed over for previous construction, likely for good reason. And finally, advanced economies tend to have more small stakeholders who have more influence - citizens have the means and motivation to raise objections to proposed projects and it's difficult to grease palms to bypass oversight. Prefabrication can help - work can be parallelized, maintaining standards is less onerous, and it causes on site construction to be less disrupting. Unfortunately the larger the structure the harder this approach is - you need more capital investment for the production facilities, there are fewer customers you can sell to, and the engineering of structures which can both adequately serve their intended purpose and be transported economically becomes more challenging. More fundamentally, everyone wants things to be better, faster, and cheaper, but you can at most pick two, and it is very difficult to get people to agree to making things worse or more expensive.