So I don't know about you, but I live in America where roads, electrical generation and transmission, water purification, and bridges are all in subpar shape.
That's super broad and I think there are complex reasons why each of these has failed, but it's pretty clear that stagnation hasn't helped and has probably actively caused harm by letting incompetence become too common in these areas.
The US has lots of infrastructure that needs repair or replacement, but there are very few areas that do not have clean water, or reliable electricity (Sans extreme weather which causes disruptions in every country), and roads and bridges are all safe to drive on (when was the last time you read about a bridge that collapsed from lack of maintenance?)
The US has its issues, but it does actually have a huge amount of superb, world class infrastructure.
That's super broad and I think there are complex reasons why each of these has failed, but it's pretty clear that stagnation hasn't helped and has probably actively caused harm by letting incompetence become too common in these areas.