I have been hearing this crumbling infrastructure crap for most of my life. I just don’t see it, and I have lived in several states in different parts of the country. Perhaps the rust belt has a problem with all that salt they use on their roads in the Winter, but down South, I don’t see it/
It’s the dams and aquaducts. NYC mainly. Old concrete and bound to give way. NYC is held together with spit and baling wire. Or duct tape, to be a little more up to date.
As with many mechanical / engineered artifacts, they function fairly well when they are at their tolerance point. However, once a tolerance boundary is traversed, then collapse is around the corner. We have had the fortune to have a country that in the last century built solid infrastructure that has lasted and served us well. That period is coming to an end. To site one example that has been mentioned before, the electrical grid often operates very close to its failure point. Only due to the extraordinary efforts of the operations staff of the major utilities do things keep running smoothly. However, a few significant failures of key components could easily push the grid over the edge. Many dams and bridges are in the same parlous state, kept safe only by dedicated operators. You may not 'see' the problems, but I can guarantee you, they are out there.