> questionable value in making things like bridges modular

Aren't most bridges these days modular and made of prefab components assembled on site? Afaik that greatly sped up construction over the past few decades.

They're also modular in that there are built-in weakpoints designed to constrain failures without taking out the whole bridge. You can see that in action if you look at photos of the Bay Bridge after Loma Prieta. Collapsed sections, but most of the bridge stayed up.