I don't know the answers, but as someone who works in the industry (on the design side). I think a big unmentioned factor is probably liability and the prospect of litigation.
If you look at old blueprints for projects in the past, they are a LOT less detailed. They had to be, because it was physically more difficult to produce them since they had to be drawn by hand. A lot was left to the contractor to figure out in the field.
Now, drawings are more detailed and contractors are incredibly reluctant to make even the smallest decisions on their own. They don't want to assume the liability and risk getting sued if they do something wrong, so they push that off on the engineers and architects.
This means every time there's a question, it has to be submitted through a formal process, tracked, answered, documented. And if the change has any cost impacts, the contractor tacks on a hefty premium because they know they can get away with it (and they probably underbid in the first place to win the job). Delays pile up, every clarification becomes an expensive change order, construction workers twiddle their thumbs while designers get around to addressing questions and this all costs money and time.
If you look at old blueprints for projects in the past, they are a LOT less detailed. They had to be, because it was physically more difficult to produce them since they had to be drawn by hand. A lot was left to the contractor to figure out in the field.
Now, drawings are more detailed and contractors are incredibly reluctant to make even the smallest decisions on their own. They don't want to assume the liability and risk getting sued if they do something wrong, so they push that off on the engineers and architects.
This means every time there's a question, it has to be submitted through a formal process, tracked, answered, documented. And if the change has any cost impacts, the contractor tacks on a hefty premium because they know they can get away with it (and they probably underbid in the first place to win the job). Delays pile up, every clarification becomes an expensive change order, construction workers twiddle their thumbs while designers get around to addressing questions and this all costs money and time.