That "Big Dig" in Boston is probably a good example. It was like... 10 years past its original schedule, wayyyy over budget... but I don't think anyone in Boston wants to go back to before it.

https://en.wikipedia.org/wiki/Big_Dig

Like any literally any infrastructure, no one is standing around going "Wow, that Interstate highway system sure was a waste of time".

Been on a road or pavement lately? Airport, railway, school, park, townhall etc.?

Someone complained that thing was a waste of money when it was built.

I don't know. Maybe something like the Interstate Highway System.

BART.